Jarv/fix elb reg

gnupg dir needs to be owned by the web user

Unfortunately this is necessary since temp files are written to this dir

Jarv/gpg perms

giving the web user permission to read the gnupg keys

renaming discern_branch

also adding certs and discern to provision

Creates a glusterfs role

edx_platform and cs_comments_service were swapped

add create_user play

Also don't run the edxapp restart handler when on workers.

Feanil/pre stage

Replace 'dev' with a variable so that we can start using the playbook with other environments.

Use the gh_users role instead of creating users in the common role.

Jarv/provision elb