Add ssl support

[eado]

Issue #35 should be resolved.

[eado]

Documentation for the new features should be available in the updated README.md.

[kmtvar]

Thank you for your ssl support. It worked very well. And here is a simple example code for a websocket client.

from websocket import create_connection
import ssl
ws = create_connection("wss://127.0.0.1:13254/", sslopt={"cert_reqs": ssl.CERT_NONE})
receive_message = ws.recv()
print(receive_message)

[Pithikos]

I think these are probably redundant? Since already set in the __init__?