Added kramdown-parser-gfm dependency
Added kramdown-parser-gfm dependency

This dependency is required to get the test suite to run successfully.

aarongustafson/jekyll-webmention_io,aarongustafson/jekyll-webmention_io,aarongustafson/jekyll-webmention_io,aarongustafson/jekyll-webmention_io