Better get typing for basic list usage

[DeviousStoat]

get is very hard to type but a very nice simple usage of the function is to maybe get a value from a list without worrying about index errors, similarly to get method for dict.
Since using the function on a list with an int path is unequivocal, this usage can be typed. This is the goal of this PR.

[coveralls]

Coverage: 100.0%. Remained the same when pulling b57ede9 on DeviousStoat:get-list into a0483e4 on dgilland:develop.

[dgilland]

@DeviousStoat One thing I realized with the getis that it supports any object. If the passed in object is not a dict or list, then it falls back to using getattr() on the object.

[dgilland]

That also means that anything that is using get may need to support a non-dict/list argument(s) (e.g. invoke can invoke a method on any object).