Providing Backwards Compatability with Python 3.6 Variable Annotations

I am trying to create a python package (not anywhere at the moment) and I want to use 3.6 python variable annotations, that is

foo: int = 5

while still providing support for Python 3.5.

Is there any way to provide these style of variable annotations inside Python 3.5, either through a

from __future__ import variable_annotations

or similar. I know it is possible to use comment type annotations, but I would like to be able to use this style.

from Providing Backwards Compatability with Python 3.6 Variable Annotations