squashing commits

devstack to not use pre_supervisor

typo error

Taking out edxapp_pypi_local_mirror, replacing with COMMON_PYPI_MIRROR_URL

Adding back - for white space

Conflicts:
	playbooks/roles/edxapp/tasks/deploy.yml
taking out paver task for now
Merge pull request #971 from edx/han/devpi

Using PyPi URL instead of DevPi
Merge remote-tracking branch 'origin/release' into feanil/merge_release_into_master
Merge pull request #981 from edx/feanil/merge_release_into_master

Feanil/merge release into master