Make ciphers configurable from the eapi.conf file

[gmuloc]

Follow up to #222

Today the only way to give ciphers to connect to a node is to define the ciphers in the ssl. Context directly and give it to connect: https://pyeapi.readthedocs.io/en/latest/client_modules/client.html?highlight=cipher#pyeapi.client.connect

It would be great to be able to do this from eapi.conf by giving a special argument used as a kwargs (right now giving a key would just blindly give the string to connect but the SSL context would not be created with it).