Add tests for enqueue feature (and other things)

[rafecolton]

This pull requests adds the following:

• refactoring of enqueue feature as well as the addition of proper tests
• use sudo: false on Travis for faster builds
• make all tests work with go test ./... (after building with -tags integration) so they don't have to be run with ginkgo
  • including rewriting some tests to not use ginkgo/gomega at all
• add code coverage stats using coveralls
• enqueue and init now work with get remotes that start with git:// (and added corresponding tests)
• remove the necessity for the webhook package to know about job.TestMode

[coveralls]

Changes Unknown when pulling bc0b8351a1d970940cc5063d0d7e10565b4adcd8 on add-tests-for-enqueue-feature into \ on master**.