Make specs run with current rspec and filetesthelper
Use new type and file specification method

The old :file key doesn't work anymore with newer ruby-graphviz, and
causes an exception.
Output generation proc needs explicit arguments
Replace calls to deprecated ruby-graphviz API
Properly sort gem nodes
Merge pull request #1 from mvz/issue-work-with-current-ruby-graphviz

Make DepGraph work with current ruby-graphviz
Bump to 0.11.0
Update master