Made json quoting prettier
Clarified expectation
Added pry as a dependency
Require pry in spec_helper
Clarified expectation
Renamed ApplicationAuthSession to ApplicationAuthentication
Added faraday_middleware as a dependency
Use faraday json middleware to parse response
Implemented the Twitter::UserGateway

Given an ApplicationAuthentication this object can fetch information
about twitter users by their screen name.
Added dotenv as a dependency
Added a .gitignore file
Require submodules
Add top-level module for the application

This module acts like a registry that knows how to instanciate different
classes to be used as defaults
Added a console executable for experimenting
Ignore .DS_Store files