Provide kanin server for failure+state management

[oubiwann]

This should start when the kanin application starts. It will track connection options, a default connection (with the ability to support more, including connection pooling in the future), a default channel (reducing channel-related function arities by one in the default case), and the ability to support more channels in the user desires.

Tasks:

• Create kanin gen_server modules and populate with base code - Create kanin gen_server modules and populate with base code #19
• Create init function that takes network options and initializes state - Create init function that takes network options and initializes state #20
• Create gen_server function for making mod:func calls to Erlang RabbitMQ libraries - Create gen_server function for making mod:func calls to Erlang RabbitMQ libraries #21
• Create special gen_server functions to support high-level API - Create special gen_server functions to support high-level API #22
• Register application

Branch:

• feature/7/kanin-server

Part of epic #4

[oubiwann]

Done.