Merge pull request #2281 from learningequality/release-0.12.0

Release 0.12.3
metadata for 0.12.3
Merge branch 'release-0.12.0'
Merge pull request #2308 from learningequality/release-0.12.0

Release 0.12.5
Merge pull request #2351 from learningequality/release-0.12.0

Release 0.12.6
Adds hipchat to travis notifications.
Updates email notifications in travis.
Adds new encrypted email for Travis notification (hopefully works this time).
Gives up on trying to encrypt email for Travis. BAH!
Merge branch 'master' into release-0.12.0