stipulate rails version in gemfile
add gem to help Serve assets
Merge branch 'dev'

* dev:
  simplecov configure
  configure simplecov
  passing integration tests for submiting proposal feature
  add failing integration test for submitting pitch feature
  pass unit tests for proposals associations
  add failing unit tests for proposals associations
Merge branch 'dev'

* dev:
  add validations for proposal submission requirements
add failing integration tests for index of proposals for a project feature
passing integration tests for displaying index of proposals to a project feature
integration tests passing for displaying proposals for a project