tqdm v4.30.0 stable

• avoid moving when leave=False
• generalise nested bar tests
• add display() helper function
• add and expose format_dict (#562, #482, #494, #656)
  • allow arbitrary keyword arguments for format_meter
  • document format_dict overriding
  • add tests for overriding
  • related: #660 #172 #587
• add and tidy developer documentation
• fix py3 CLI pipe decoding error (#663)
• framework overhaul (developing, testing, Travis CI updates)
• tidy code and style (flake8)
• setup.py refactor
  • setup.py make
    • add support for multi-line commands
    • tidy and efficiency
  • replace setup.py's built-in make -> py-make>=0.1.9 (#290)
  • add requirements-dev.txt and extras_require[dev]
• add, update and tidy tests
• include interactive Jupyter demonstration (#652 -> #659)
• update documentation
  • add FAQ about py2 pipes (#359)
  • add badges
  • update examples
  • update authors