Refactored @BillXMA availability PR, added tests, and refactored camping.py

[colossatr0n]

• Refactored specifying campsite IDs. Original implementation was done by BillXMA here.

• Added argument to output campsite IDs with their availability (--show-campsite-info):

  
  $ python camping.py --start-date 2018-07-20 --end-date 2018-07-23 --parks 232448 232450 232447 232770 --show-campsite-info --nights 1 
  There are campsites available from 2018-07-20 to 2018-07-23!!!
  🏕 ELK CREEK CAMPGROUND (SAWTOOTH NF) (232042): 1 site(s) available out of 1 site(s)

• Site 69800 is available on the following dates:

  • 2018-07-20 -> 2018-07-21
  • 2018-07-21 -> 2018-07-22

• Refactored camping.py:

  • Moved web requests into RecreationClient.
  • Converted constant strings to enums.
  • Moved utility functions into utility files.
  • Moved argparse logic into its own class.

  Added tests.

[colossatr0n]

Thanks a lot for all of these changes, this is a much needed quality of life improvement. I don't have any major changes I'd like to see, just some nits.

No problem! Thanks for maintaining this repo.

Have you verified that the output without the new flags is the same and still works with the notifier?

Let me double check.

[banool]

Thanks for checking. I'd love to make the notifier take some structured input, json at the least, to make changes to the main script less likely to break it. As it is now, it does very janky parsing of the human readable output. But for now we have to be careful.

[colossatr0n]

Output without the new flags is the same and the notifier still works.

[banool]

Perfect. Rebase this PR since there are conflicts and then we'll be good to go.

[colossatr0n]

Rebased 👍

[banool]

Thanks for working on all these changes!!

[colossatr0n]

You're welcome! Thanks for accepting the PR.