To be clear, Atlantis was compatible with 0.12 before this commit, but
this change makes 0.12 the default version *if* users haven't set the
--default-tf-version flag.
* Adding docker image and release scripts
* Using circleci version 2
* now building dumb-init and gosu from source
* trying to fix e2e tests
* fixing working directory for circleci version 2
* start atlantis server and ngrok in the background
* Adding terraform to path and removing old decryption method for circleci
* adding terraform binary to the correct path
* ATLANTIS_URL is now being exported
* using circleci version 2 syntax to export variable
* using circleci version 2 syntax to export variable
* ngrok isnt working now
* Updating CHANGELOG
* Fixes after review and updated README.md
* Adding e2e tests back and upgrading terraform version 0.9.11
* Fixing the binary name for e2e tests
* revert binary name change
* missed indentation for makefile
* use owner name for branch head for pull request creation
