Testcase: ``` python In [1]: from pycipher import ADFGVX In [2]: ADFGVX().encipher('1') Out[2]: '' ``` I would expect the ciphertext to not be empty, as ADFGVX supports numbers. I believe the issue was introduced [here](https://github.com/jameslyons/pycipher/commit/d80d05e3ec87fea84df3473ee5eb343ff7d7d887#diff-649356aea688c6797aa6ec7713e9321aL46) and [here](https://github.com/jameslyons/pycipher/commit/d80d05e3ec87fea84df3473ee5eb343ff7d7d887#diff-649356aea688c6797aa6ec7713e9321aL61). Without the filter argument, remove_punctuation filters out any numbers.
Testcase:
I would expect the ciphertext to not be empty, as ADFGVX supports numbers.
I believe the issue was introduced here and here. Without the filter argument, remove_punctuation filters out any numbers.