Fix monocypher.argon2i_32

[ioerror]

While using pymonocypher for a cryptographic protocol, we encountered an AttributeError:

File "c_monocypher.pyx", line 328, in monocypher.argon2i_32

AttributeError: 'dict' object has no attribute 'nb_block'

Using the Python console to reproduce the error with monocypher 4.0.2.3:

import monocypher
monocypher.argon2i_32(nb_blocks=100000, nb_iterations=3,
password=password, salt=salt, key=None,
ad=None)

This will result in the following exception:

Traceback (most recent call last):
File "", line 1, in
File "c_monocypher.pyx", line 328, in monocypher.argon2i_32
AttributeError: 'dict' object has no attribute 'nb_block'

It appears that the c_monocypher.pyx is defined in the singular 'nb_block' for the binding when it should be 'nb_blocks'. After changing that value to 'nb_blocks', it works as expected:

password = b'123456'
salt = b'00125235'
monocypher.argon2i_32(nb_blocks=100000, nb_iterations=3,
password=password, salt=salt, key=None,
ad=None)

This produces a bytes object as expected:

b'\x8cj\x88\xc7\xda}\x7f\x18Z\x01\xbf\xbb\xd5\x01\x13\xd9<\xb4\xb9'c\x8f\x98\xee\x96\x04E-\xfc"\xd9o'

[mliberty1]

Thank you for the pull request. It looks like no one has used argon through pymonocypher yet!

I added a simple unit test and released 4.0.2.4. You should be able to upgrade using:

pip install -U pymonocypher