Log Message:
py-fonttools: update to 3.16.0

3.16.0:
[head] Try using SOURCE_DATE_EPOCH environment variable when setting the head \ 
modified timestamp to ensure reproducible builds.
[VTT] Decode VTT’s TSI* tables text as UTF-8.
Added support for Graphite font tables: Feat, Glat, Gloc, Silf and Sill.
[varLib] Default to using axis “name” attribute if “labelname” element \ 
is missing.
[merge] Added support for merging Script records. Remove unused features and \ 
lookups after merge.
Added fontTools.svgLib package. Includes a parser for SVG Paths that supports \ 
the Pen protocol. Also, added a snippet to convert SVG outlines to UFO GLIF.
[AAT] Added support for ankr, bsln, mort, morx, gcid, and cidg.
[subset] Implemented subsetting of prop, opbd, bsln, lcar.