Migrate countries

[fw42]

Migrate countries to the current version of the list of wca-states (also see https://github.com/thewca/worldcubeassociation.org/pull/1650).

Checking our production database, there is exactly four countries that need to be migrated:

irb(main):041:0> countries = Country.pluck(:name);
irb(main):042:0* wca_countries = Wca::Country.pluck(:name);
irb(main):043:0* competitor_country_ids = Competitor.pluck('distinct(country_id)');
irb(main):044:0* competition_country_ids = Competition.pluck('distinct(country_id)');
irb(main):045:0* Country.where(name: countries - wca_countries).where(id: competitor_country_ids + competition_country_ids).map(&:name)

=> ["Aruba", "Korea", "Puerto Rico", "USA"]

Those countries are renamed as follows (see the code in this PR):

CHANGES = {
  "Aruba" => "Netherlands",
  "Korea" => "Republic of Korea",
  "USA" => "United States",
  "Puerto Rico" => "United States"
}

The migration consists of the following steps:

• (1) Import all missing countries from the WCA database, i.e. for each country name in the WCA database, create a new country with the same name in our database (unless a country with that name already exists).
• (2) For all competitors and all competitions with one of the above four countries, use the country with the new name instead (note that this does not rename the old country but rather change the country association of the model to the corresponding newly created country).
• (3) Delete all countries in our database for which no country of the same name exists in the WCA database (this will delete 22 countries from our database, none of which should have any competitors or competitions anymore at that point).

[fw42]

@Laura-O @jfly @linusfresz, if one of you had a moment to take a quick look at this, that would be great.

[fw42]

@Laura-O @LinusFresz, any comments? does this look correct to you?

[Laura-O]

Yes, looks good! Thanks!

[fw42]

      01 == 20170709195655 MigrateCountries: migrating =================================
      01 Creating Antigua and Barbuda
      01 Creating Burundi
      01 Creating Cabo Verde
      01 Creating Democratic People’s Republic of Korea
      01 Creating Democratic Republic of the Congo
      01 Creating Federated States of Micronesia
      01 Creating Guinea Bissau
      01 Creating Holy See
      01 Creating Republic of Korea
      01 Creating Kyrgyzstan
      01 Creating Maldives
      01 Creating Palau
      01 Creating Rwanda
      01 Creating Seychelles
      01 Creating Tajikistan
      01 Creating Timor-Leste
      01 Creating Turkmenistan
      01 Creating United States
      01 Renaming Aruba to Netherlands
      01 -> Changing Competitor 5814 from Aruba (10) to Netherlands (128)
      01 -> Changing Competitor 5869 from Aruba (10) to Netherlands (128)
      01 -> Changing Competitor 5887 from Aruba (10) to Netherlands (128)
      01 Renaming Korea to Republic of Korea
      01 -> Changing Competitor 2159 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 2160 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 4229 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 4230 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 4425 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 5055 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 6994 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 7677 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 7900 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 9007 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 9008 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 9009 from Korea (95) to Republic of Korea (213)
      01 -> Changing Competitor 10038 from Korea (95) to Republic of Korea (213)
      01 Renaming USA to United States
      01 -> Changing Competitor 644 from USA (192) to United States (222)
      01 -> Changing Competitor 1040 from USA (192) to United States (222)
      01 -> Changing Competitor 1311 from USA (192) to United States (222)
      01 -> Changing Competitor 1312 from USA (192) to United States (222)
      01 -> Changing Competitor 1993 from USA (192) to United States (222)
      01 -> Changing Competitor 2021 from USA (192) to United States (222)
      01 -> Changing Competitor 2293 from USA (192) to United States (222)
      01 -> Changing Competitor 2344 from USA (192) to United States (222)
      01 -> Changing Competitor 5686 from USA (192) to United States (222)
      01 -> Changing Competitor 5729 from USA (192) to United States (222)
      01 -> Changing Competitor 5730 from USA (192) to United States (222)
      01 -> Changing Competitor 5751 from USA (192) to United States (222)
      01 -> Changing Competitor 6675 from USA (192) to United States (222)
      01 -> Changing Competitor 6869 from USA (192) to United States (222)
      01 -> Changing Competitor 7342 from USA (192) to United States (222)
      01 -> Changing Competitor 7343 from USA (192) to United States (222)
      01 -> Changing Competitor 7344 from USA (192) to United States (222)
      01 -> Changing Competitor 7531 from USA (192) to United States (222)
      01 -> Changing Competitor 7533 from USA (192) to United States (222)
      01 -> Changing Competitor 7680 from USA (192) to United States (222)
      01 -> Changing Competitor 8002 from USA (192) to United States (222)
      01 -> Changing Competitor 8167 from USA (192) to United States (222)
      01 -> Changing Competitor 8168 from USA (192) to United States (222)
      01 -> Changing Competitor 8250 from USA (192) to United States (222)
      01 -> Changing Competitor 8291 from USA (192) to United States (222)
      01 -> Changing Competitor 8508 from USA (192) to United States (222)
      01 -> Changing Competitor 8510 from USA (192) to United States (222)
      01 -> Changing Competitor 8522 from USA (192) to United States (222)
      01 -> Changing Competitor 8571 from USA (192) to United States (222)
      01 -> Changing Competitor 8572 from USA (192) to United States (222)
      01 -> Changing Competitor 8695 from USA (192) to United States (222)
      01 -> Changing Competitor 9141 from USA (192) to United States (222)
      01 -> Changing Competitor 9142 from USA (192) to United States (222)
      01 -> Changing Competitor 9247 from USA (192) to United States (222)
      01 -> Changing Competitor 9293 from USA (192) to United States (222)
      01 -> Changing Competitor 9703 from USA (192) to United States (222)
      01 -> Changing Competitor 9731 from USA (192) to United States (222)
      01 -> Changing Competitor 9999 from USA (192) to United States (222)
      01 -> Changing Competitor 10063 from USA (192) to United States (222)
      01 -> Changing Competitor 10120 from USA (192) to United States (222)
      01 -> Changing Competitor 10515 from USA (192) to United States (222)
      01 -> Changing Competitor 10540 from USA (192) to United States (222)
      01 -> Changing Competitor 10559 from USA (192) to United States (222)
      01 -> Changing Competitor 10560 from USA (192) to United States (222)
      01 -> Changing Competitor 10561 from USA (192) to United States (222)
      01 -> Changing Competitor 10681 from USA (192) to United States (222)
      01 -> Changing Competitor 10737 from USA (192) to United States (222)
      01 -> Changing Competitor 10784 from USA (192) to United States (222)
      01 -> Changing Competitor 10927 from USA (192) to United States (222)
      01 -> Changing Competitor 10984 from USA (192) to United States (222)
      01 -> Changing Competitor 11005 from USA (192) to United States (222)
      01 -> Changing Competitor 11006 from USA (192) to United States (222)
      01 -> Changing Competitor 11010 from USA (192) to United States (222)
      01 -> Changing Competitor 11011 from USA (192) to United States (222)
      01 -> Changing Competitor 11029 from USA (192) to United States (222)
      01 -> Changing Competitor 11418 from USA (192) to United States (222)
      01 -> Changing Competitor 11606 from USA (192) to United States (222)
      01 -> Changing Competitor 11608 from USA (192) to United States (222)
      01 -> Changing Competitor 11706 from USA (192) to United States (222)
      01 -> Changing Competitor 11707 from USA (192) to United States (222)
      01 -> Changing Competitor 11713 from USA (192) to United States (222)
      01 -> Changing Competitor 11714 from USA (192) to United States (222)
      01 -> Changing Competition 93 from USA (192) to United States (222)
      01 Renaming Puerto Rico to United States
      01 -> Changing Competitor 9834 from Puerto Rico (148) to United States (222)
      01 -> Changing Competitor 10610 from Puerto Rico (148) to United States (222)
      01 -> Changing Competitor 10612 from Puerto Rico (148) to United States (222)
      01 -> Changing Competitor 10743 from Puerto Rico (148) to United States (222)
      01 -> Changing Competitor 11102 from Puerto Rico (148) to United States (222)
      01 -> Changing Competitor 11103 from Puerto Rico (148) to United States (222)
      01 == 20170709195655 MigrateCountries: migrated (0.8427s) ========================

[fw42]

Ok, all done, sorry this took so long