WRT dictdiffer vs Dictdiffer, PEP-8 seems to suggest using all lowercase names even for package names:
Modules should have short, all-lowercase names. Underscores can be used in the module name if it improves readability. Python packages should also have short, all-lowercase names, although the use of underscores is discouraged.
So I guess I change setup.py back to
inpsirehepusecase we need to a relase that includes this inveniosoftware/dictdiffer#71