Routes with symbols produces a silent fail

If you specify :action as a symbol, Rails won't fail, you will get the Rails view but the controller/action specified won't be executed, so it's really difficult to diagnose if you don't know about it.

The problem is not that routes should accept symbols, but the weird behaviour you get as a result.

This path just converts the symbols to strings when adding routes (test included).

For more info see #692 Defining routes with symbols failes