_UpdateModDependencyGraph is not recursively called so there is no need to check to see if the module getting its dependency graph updated is the root module. UpdateModDependencyGraphRecursively handles the recursive logic checks.

Tested with a module with a circular dependency and no issues where found.
Merge pull request #6 from leftler/dropdown-fix

Fix for issue #3
Add .gitignore to submodule.
Merge pull request #8 from Ormira/gitignore

Add .gitignore to submodule.