Adds Artist’s Country of Origin field to Drawings

[steverabino]

• Adds Country of Origin field
• Removes inconsistency in drawing show view
• Removes inconsistencies in select box default values on drawing edit view

Addresses issue: #141

What this does

• [x] Adds Country of Origin
  • Gives priority in dropdown to Afghanistan, Iraq, and Syria in same way as Country drawn in give priority to Greece, Serbia, and Hungary
• [x] Removes inconsistency in drawing show view
  • Drawing show view will not show "n/a" for countries if not selected to keep in line with other fields
• [x] Removes inconsistencies in select box default values on drawing edit view
  • All select boxes on the drawing edit view now use -- select this thing -- to show an action is required

Deploy Instructions

• Will require bundle exec rake db:migrate to update the database with the new field
• Will require server restart to initialise the new constant TOP_ORIGIN_COUNTRIES

Discussion points

1. We now have in our Drawing model a "country" to show country drawn in, and "origin_country" to show origin of artist - do we need to improve the clarity of this wording?
2. Any other countries we should be giving priority to on the dropdown for this new field?
3. In defiance of #141, I added the field under "Gender" instead of under "Age", as I feel Age and Gender are too closely related to be separated on the forms

Screenshots

[CathMollie]

@stevesmith2609

• Think the priority countries are right.
• Will you close #141?
• Wording for 'Country drawn in' could change to 'Current location' perhaps

[steverabino]

Thanks, #141 closed!