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
Increase sleep time in test_delete_group test, to try to help Travis.
Merge branch 'release-0.12.0' of github.com:learningequality/ka-lite into release-0.12.0
Styling tweaks to mitigate impact of bootstrap on top navbar.
in delete button tests: make sure teacher is part of facility
use an updated version of firefox for travis
Adds wait for alert_is_present on generic method for accepting
modal dialogs.

Conflicts:
	kalite/testing/browser.py
simplify test_delete_facility test
simplify test_delete_group test
metadata for 0.12.6
Merge pull request #2353 from learningequality/release-0.12.0

Release 0.12.0 to Nalanda RCT 2
Merge pull request #2351 from learningequality/release-0.12.0

Release 0.12.6
Add `hacks_for_phantomjs()` method.
Merge pull request #2373 from mrpau/hotfix/add_phantomjs_hacks

Add `hacks_for_phantomjs()` method for `release-0.12.0` branch.
Initial fix to make a POST request when deleting a facility.
Adds hipchat to travis notifications.
Updates email notifications in travis.