v1.3.0

Updated minimum required dependencies:

fonttools >= 3.15.1
- [varLib] Add default mappings to all axes in avar to fix rendering issue
  in some rasterizers (19c4b377, 04eacf13).
- [varLib] Flatten multiple tail PairPosFormat2 subtables before merging
  (c55ef525).

ufo2ft >= 0.6.2
- Use preferred family and subfamily to compose the full name; make
  UniqueID fallback less verbose (#148).
- Import and merge any TTX found in `data/com.github.fonttools.ttx` in the
  generated OpenType font (#142).

glyphsLib >= 1.8.0
- Fixed random order of propagated anchors on python 3 (#207).
- Correctly set instances' OS/2 weight and width class using values from
  the Instances tab's "Weight" and "Width" drop-down menus.
- No longer set OS/2 Weight and With Class for generated master UFOs,
  as those are only defined for instances in Glyphs.app.
- Generate UFO's `styleMapFamilyName` and `styleMapStyleName` attributes
  using values from the Instances tab's Style Linking section.
- Support shortened versions of all the `openTypeName*` custom parameters.