Add type hints to function definitions

[jack89roberts]

Move towards including typehints in AIrsenal function definitions, i.e. from this:

def foo(x, y, z):
   print(x, y, z)
   return z

to this:

def foo(x: int, y: float, z: str) -> str:
   print(x, y, z)
   return z

[jack89roberts]

See #445

[rchan26]

Got a bit of free time this week to work partially on this - I'll do the fill_* scripts in airsenal/scripts/

[rchan26]

Have also done make_* scripts in airsenal/scripts