Simplify conditionals and loops
Move constant to module level
Simplify another conditional
Add docstrings to all functions and classes
Add functions for version parsing/formatting
Attach the expected Emacs version to the exception
Check supported Python version
Merge branch 'refactor-bin-cask'

* refactor-bin-cask:
  Check supported Python version
  Attach the expected Emacs version to the exception
  Add functions for version parsing/formatting
  Add docstrings to all functions and classes
  Simplify another conditional
  Move constant to module level
  Simplify conditionals and loops