HandleCreateRoleSuccessfully creates an HTTP handler at `/roles` on the test handler mux that tests role creation.

HandleDeleteRoleSuccessfully creates an HTTP handler at `/roles` on the test handler mux that tests role deletion.

HandleGetRoleSuccessfully creates an HTTP handler at `/roles` on the test handler mux that responds with a single role.

HandleListRoleAssignmentsSuccessfully creates an HTTP handler at `/role_assignments` on the test handler mux that responds with a list of two role assignments.

HandleListRolesSuccessfully creates an HTTP handler at `/roles` on the test handler mux that responds with a list of two roles.

HandleUpdateRoleSuccessfully creates an HTTP handler at `/roles` on the test handler mux that tests role update.

CreateRequest provides the input to a Create request.

GetOutput provides a Get result.

ListOutput provides a single page of Role results.

UpdateOutput provides an update result.

UpdateRequest provides the input to as Update request.

ExpectedRoleAssignmentsSlice is the slice of role assignments expected to be returned from ListAssignmentOutput.

ExpectedRolesSlice is the slice of roles expected to be returned from ListOutput.

FirstRole is the first role in the List request.

FirstRoleAssignment is the first role assignment in the List request.

SecondRole is the second role in the List request.

SecondRoleAssignemnt is the second role assignemnt in the List request.

SecondRoleUpdated is how SecondRole should look after an Update.