Fix HTTP response error handling

Fixes #9

Multi client API

This release breaks API as it requires to pass client pid to all functions. This allows running multiple clients in parallel using different credentials.

Enable lager logging

• include lager dependency
• log basic operations
• include test specific profile

Public release

REST API calls that are implemented now:

• oAuth support (extracted into separate module for using in apps with Twitter based login)
• Home timeline
• Mentions timeline
• Status lookup
• Search API