GRN2-176: Create a role editor that allows admins to specify what permissions each role has (#709)

* Add roles editor

* Add colour selection ability to roles

* Add ability to assign roles to users in the UI

* Remove rolify and replace it with our own custom roles implemenation

* - Fix all existing roles functionality
- Fix super admins

* Fix bugs with new customers not have default roles

* Add can't create room setting

* Code improvements

* Fix migration

* Add tests for new methods

* Translate reserved role names

* Pull roles from saml/ldap

* Fix rspec

* Fix scrutinizer issues

* Fix email promoted/demoted tests

* Apply comments

* Redirect directly to the main room

* Add comments

app/views/user_mailer/user_demoted.html.erb

@@ -21,11 +21,11 @@
     <%= image_tag(@image, height: '70') %>
 
     <h1 style="margin-bottom:30px">
-      <%= t('mailer.user.demoted.subtitle') %>
+      <%= t('mailer.user.demoted.subtitle', role: @role) %>
     </h1>
 
     <p>
-      <%= t('mailer.user.demoted.info', url: @url) %>
+      <%= t('mailer.user.demoted.info', url: @url, role: @role) %>
     </p>
 
     <p style="margin-bottom:45px;">