Eliminate usage of crypt library

[ekos2001]

Because of the crypt library is not available on Windows, I'm receiving an error in HA
2020-08-03 00:45:40:0100 700 2020-08-03 00:45:39 ERROR (MainThread) [homeassistant.config_entries] Error occurred loading configuration flow for integration homekit_controller: The crypt module is not supported on Windows

As I can see, it is used in one place only to generate a salt in the aiohomekit/aiohomekit/crypto/srp.py
salt = crypt.mksalt(crypt.METHOD_SHA512)[3:]

May be it can be replaced with different implementation?

[Jc2k]

crypt is built in to python so it's a real shame they don't have an implementation on Windows. I suggested an alternative for homekit_python (the synchronous/blocking library aiohomekit was based off of) here. But I don't have Windows to test, and i've been struggling a bit for time.

Are you able to test the suggestion I made? Or even better submit a PR?

[ekos2001]

I tested your suggestion and made PR #15

[Jc2k]

Thank you very much! I've merged this, and i'll do a release and get it into Home Assistant as soon as i can.