Add course api endpoint

[#13]
Add course serializer

[#13]
Make Ember adapter point to the right place

[#13]
Add model for Courses

[#13]
Add route for Courses

[#13]
Add view for Courses

[#13]
Add courses to router

[#13]
Add link to courses route

[Finishes #13]
Merge pull request #16 from gschorkopf/killpack/courses

Killpack/courses
Removes rails view, updates ember template for courses
Removes "Welcome to Frolfr" header
Feature spec for the rounds
Rendering the rounds template