Group with Looking For Team Members

Instead of having to invite someone: as a group, state that you are looking for members.

• Add looking for team members column to Groups.
• Added boolean to en.yml.
• Added looking for team to group dashboard settings.
• Change layout of group that is looking for members.
• Add callback to groups which updates looking_for_members to false if the group is approved
• Added edit to admin for looking_for_members.