isAction(Just)?(Pressed|Released) don't work

Maybe it's just something I'm doing or not doing, but I cannot get any of the `isActionPressed` methods to work.

Minimal example:

```nim
import godot, node
import input, scene_tree

gdobj Arena of Node2d:
  method process(dt: float64) =
    if isActionJustPressed("ui_cancel"):
      print "quit"
      getTree().quit()
```