v2.3.0

• Added --flatten-components option to flatten nested composite glyphs
  so that they have maximum component depth of 1 (#714).
• Bumped minimum requirements:
  • fonttools >= 4.18.1
    https://github.com/fonttools/fonttools/releases/tag/4.16.0
    https://github.com/fonttools/fonttools/releases/tag/4.16.1
    https://github.com/fonttools/fonttools/releases/tag/4.17.0
    https://github.com/fonttools/fonttools/releases/tag/4.17.1
    https://github.com/fonttools/fonttools/releases/tag/4.18.0
    https://github.com/fonttools/fonttools/releases/tag/4.18.1
  • glyphsLib >= 5.3.0
    https://github.com/googlefonts/glyphsLib/releases/tag/v5.3.0
  • ufo2ft >= 2.19.1
    https://github.com/googlefonts/ufo2ft/releases/tag/v2.18.0
    https://github.com/googlefonts/ufo2ft/releases/tag/v2.18.1
    https://github.com/googlefonts/ufo2ft/releases/tag/v2.19.0
    https://github.com/googlefonts/ufo2ft/releases/tag/v2.19.1