Adds managership scaffold

[#46971655]
Adds 3 default venue managers to seed - Each default venue has a manager

[#46971655]
Adds restrictions on band creation

[#46971655]
Adds restrictions to venues controller - Managers is created when Venue is created

[#46971655]
Band Participation is created along with Band creation

[#46971655]
Fixes bug when too many requests to Gmaps - Adds virtual attribute skip_geocoding which is used in seed

[#46971655]
Fixes all tests and adds some new ones for managership

[#46971655]
Merge pull request #11 from WilfriedDeluche/managership-46971655

[Fixes #46971655] Managership 46971655
Installs carrierwave and rmagick - Adds uploader and new model VenueImage

[#39944449]
Revert "Installs carrierwave and rmagick - Adds uploader and new model VenueImage"

This reverts commit 32e1c1c4572f9e4a2e5f0d12edff3870655d436a.

[#39944449]
Revert "Revert "Installs carrierwave and rmagick - Adds uploader and new model VenueImage""

This reverts commit e0df486a25af7eadaa2da5992546d3f27112bdab.

[#39944449]
Adds controller for VenueImage - Can create, show and list index

[#39944449]
CSS for images on venue show page

[#39944449]
CSS for venue images show pages

[#39944449]
Adds previous and next image to show page

[#39944449]
Implements destroy venue image

[#39944449]
Is main set as false by default - Implements set_main action

[#39944449]
One sidebar partial in shared folder - Adds some i18n - Highlights main picture for venue

[#39944449]
Shows main picture if exists on venues index page

[#39944449]
Adds venue main image to seed

[#39944449]