Fixes to grab source for bundled graphviz-devel from github
Fixes to grab source for bundled graphviz-devel from github

shahin/deepdive,sky-xu/deepdive,HazyResearch/deepdive,sky-xu/deepdive,shahin/deepdive,HazyResearch/deepdive,HazyResearch/deepdive,HazyResearch/deepdive