Make @public mypy compatible

Sample code snippet:

from public import public

@public
def fun(x: int) -> None:
    print(x * 2)

fun(4)

mypy run:

> mypy .\nyuba\nyuba_mypy.py
nyuba\nyuba_mypy.py:7: error: "ModuleAware" not callable
nyuba\nyuba_mypy.py:7: error: "None" not callable
Found 2 errors in 1 file (checked 1 source file)