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
Initial fix to make a POST request when deleting a facility.
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
Merge branch 'release-0.12.0' into hotfix/2198-Deleting-a-facility-should-NOT-use-a-GET-request
Add tastypie package.
Merge pull request #2382 from mrpau/hotfix/2198-Deleting-a-facility-should-NOT-use-a-GET-request

Fix to make a POST request when deleting a facility.
Handle function or list from psutil
Add comment to help future maintainers
Merge pull request #2409 from dylanjbarth/fix_psutil

Handle function or list from psutil
Revert "Add tastypie package."

This reverts commit b0712abe5ee4dabacba57fbe521cf3a6f2027bee.
checkout tastypie from nalanda-rct2
Prevent students from changing their group