Decouple tests from unspecified data ordering

These tests have been passing with SQLite, but don't reflect guaranteed
behavior and with PostgreSQL failed intermittently.

spec/controllers/api/v1/rooms_controller_spec.rb

@@ -17,9 +17,7 @@ describe Api::V1::RoomsController do
 
         expect(response).to be_success
 
-        expect(json.length).to eq(2)
-        expect(json[0]['name']).to eq('Conference Room')
-        expect(json[1]['name']).to eq('Test Room')
+        expect(json.map { |r| r['name'] }).to contain_exactly('Conference Room', 'Test Room')
       end
     end