1.2.0

• Introduced filename conflict resolution via sequential filenaming
  in response to #9
• Fixed incorrect calculation of modified time on some systems #10
• Deprecated the --overwrite flag
• Added support for passing globs to rename_dir, exposed via the
  --glob cli flag. This option will override --recursive and allow
  for greater control of file processing (thanks to @TotallyInformation
  for the suggestion).
• Reduced size of test/demo images
• Upgraded most dependencies
• Swapped out Grunt-based tooling for npm scripts