Bug In foursquare.py, Line 27

[Th3Tr1ckst3r]

>>> from pycipher import Foursquare
>>> ciphertext = Foursquare(key1='zgptfoihmuwdrcnykeqaxvsbl',key2='mfnbdcrhsaxyogvituewlqzkp').encipher('Hello World!')  
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/linuxuser/.local/lib/python3.9/site-packages/pycipher/foursquare.py", line 49, in encipher
    a,b = self.encipher_pair(string[c],string[c+1])
  File "/home/linuxuser/.local/lib/python3.9/site-packages/pycipher/foursquare.py", line 27, in encipher_pair
    return (self.key1[arow*5+bcol], self.key2[brow*5+acol])
TypeError: list indices must be integers or slices, not float