v1.14.1

Full Changelog

Merged pull requests:

• Accept open-uri as create_rich_menu_image's argument #177 (yskkin)
• Update rake requirement from ~> 10.4 to ~> 13.0 #176 (dependabot-preview[bot])
• Update webmock requirement from ~> 1.24 to ~> 3.8 #175 (dependabot-preview[bot])
• Quit top level reference #174 (koheisg)