Create manifest of cards per expansion.

Use manifest for populating the sources array.
Collection object to track user's collection.
Don't bail when releasing a type we haven't used.
Stubs for backend support.
Unit test for collections API.
Backend support and UI. #58

Fix tests.
Fix collection logic so that it adds expansions properly.
Still need to make collections be authenticated-only.
Only show collections button when authed and ready.
Save 1 second after user has updated collection.

Use @elistevens' silly coloring scheme.
Clear `background-color` CSS when count is 0.
Row in modal should also be fluid.
Fix typos in manifest.
Compile artifacts; update readme.
Merge branch 'feature/58_collections'

fixes #58