Add C#, D and Julia languages into matrix.
Send builds to containers and enable caching gems
Merge pull request #313 from simi/add-new-languages-to-matrix

Add C#, D and Julia languages into matrix.
added default avatar and hid hiring
compile the images/ui directory as well
changing default gravatar from svg to png
Merge branch 'master' of github.com:travis-ci/travis-web
added png
Auto-merged master into ja-build-header on deployment.