fix bugs related to get_module_name and resolve_imports

[CannedFish]

get_module_name

Will replace all .py in a path like /path/to/wheel-0.37.1-py2.py3-none-any/wheel/**/*.py, which will make files can't be found from a wrong path (/path/to/wheel-0.37.1-py23-none-any/wheel/**/*).

resolve_imports

Will raise a KeyError sometimes.