.actions() has nonsense response when used on a state with no actions

[StoneCypher]

As expected:

> const bar = jssm.from(`a 'quuz' -> b;`, {data: 'bob'});
undefined

> bar.actions();
[ 'quuz' ]

> bar.actions('a');
[ 'quuz' ]

Failing:

> bar.actions('b');
Uncaught JssmError: No such state "b" (at "a")
    at Machine.actions (C:\Users\john\projects\jssm\dist\jssm.es5.cjs.js:1:303480) {
  base_message: 'No such state "b"',
  requested_state: undefined
}

Blocks #703