0.4.0

Updated CLI options to be more consistent and intuitive
Moves hardcoded values to a YAML configuration file
This is a pre-requisite for testing and additional feature work

• Remove hardcoded values from code
  • They were either eliminated or moved to config file
  • There are still 3 places I've identified that still use hard-coded values, but they all have issues created for them
    • #50
    • #65
    • #66
• Update CLI options
  • Add new CLI options
    • --upstream-since
    • --downstream-since
    • --config
  • Removed CLI option
    • --since
  • Consolidated updates to downstream targets under downstream subcommand
  • Moved all options to subcommands to improve usability
    • Defined once in code
• Moved subcommand functionality to classes to better support state
• Moved config, database, and repo definitions to top level rather than direct global access