Add travis config
Add serializer for posses

We were serving json successfully without serializers but with AMS
there appear to be no defaults.  'embed ids' is required for Ember Data.
Fix request spec for PossesController#show
Fix coderunner test

This is possibly a temp fix, there is some weirdness with turning
a simple string in JSON.  JSON.parse doesn't work for whatever is
returned from answer.to_json, so for now removing the quotes was a
solution to get tests passing again.  Also modifies from get to post
based on recent changes.
Clean up request specs
Make whitespace/indenting consistent
Add ProblemSerializer; fix resulting broken spec
Add serializer for solutions; update specs
Fix merge conflicts
Fix merge conflicts; Fix solutions create request spec
Update travis
Add postgres to travis.yml
update travis
Merge pull request #3 from whaambang/serializers

Serializers