v2.1.0

• Automatically resolve .best property
• Pass Content-Length header with POST requests
• Fix install instructions with git clone
• Add functionality for single threaded testing
• Add debug support to show if a URL request resulted in a redirect
• Add the python version to the version output
• Switch from platform.system to platform.platform when building the User-Agent header
• Don't pass server_hostname to ssl.wrap_socket
• ensure ERROR doesn't print an empty string