Fix emails being sent with the wrong mail address, fix #713

All emails have to be sent with the email configured in the Site. Spams
and feedbacks were being sent with the email of the user that created the
spam/feedback. This fails for some SMTP servers and is wrong.
Add .ruby-version
Merge branch 'master' into recordings
Rooms' 'meetingid' are now fixed and globally unique

Update made in bigbluebutton_rails, see #734 and #735.