Fix ticket comment permissions for non-admins. #1255.
Implement New Permissions Per Updated Google Doc

* Removing has_and_belongs_to_many relationship between users and roles, and replacing with a one-to-many relationship.
* Adding read_only role to main seed file. Will need to run db:seed task to add it to staging and production
* Adding migration to handle removing CSR role, adding read_only role, and migrating existing users from the former to the latter
* Updating ability file to match ability matrix document
* Adding open capacity ability tests
* Adding provider ability tests
* Adding provider relationship ability tests
* Adding services ability tests
* Adding empty test for service request abilities
* Adding trip claim ability tests
* Adding empty test for trip results abilities
* Adding trip ticket ability tests
* Adding trip ticket comment ability tests
* Adding empty test for waypoint abilities
* Adding user ability tests
* Removing old combined ability test
* Reorganizing abilities to accommodate more restrictive site_admin permissions
Merge branch '1267-implement-new-permissions-per-updated-google-doc'

Conflicts:
	app/models/ability.rb
	test/unit/ability_test.rb
Change trip claim status from -1,0,1 to text representation

* Transforming TripClaim.status field from an integer to a string
* Updating tests. Making sure that the status is always represented as a symbol for the sake of easy comparisons and validation
Fixing broken form template related to previous commit
Minor change to layout of audit trail table
Minor changes to form CSS and trip_ticket form partial
Design tweaks
Don't count a provier's denied/rescinded claims as claims to a ticket. #1212.
Tweak left margin of main page content so it lines up.
More claim status and role fixes to make all tests pass.
Move messages placeholder number to zero for now.

Since messages/notifications aren't implemented, don't make users
think they have 3 notifications.
Fix actionmailer staging URL. #1101.
Fix button alignment in firefox.

We should be forced to include the vertical-align statement anyway,
but Chrome is extremely forgiving.
Locking down Grape gem
implementing Black/White lists for trip tickets
Removing duplicate auto approval process
Merge branch 'master' of github.com:rideconnection/clearinghouse into 1041_api_crud_for_trips

Conflicts:
	app/controllers/trip_tickets_controller.rb
	app/models/ability.rb