JITB-8: Support for Quiplash 2

[hark130]

• Modularized legacy features
  • Common web driver interactions extricated into a new jitb_selenium module
• Added new misc features
  • The --debug flag now gives the user a chance to react (e.g., save a web page) before jitb exits.
• Added a modular test framework
  • Mostly unit test work
• Added file-based test input (saved actual Jackbox web pages for testing)
• Wrote ~200 unit tests for various functions (all tests passing)
• Implemented a linter script
• Made the linters (mostly) happy
• Started source-controlling debug logs to help facilitate future work (e.g., better fill in the blank responses)
• Implemented support for Quiplash 2
  • Defined an abstract base class (ABC) for Jackbox game classes
  • Refactored legacy code
  • Polished the implementation of legacy code