Add tests for normalized package name resolution
Add tests for normalized package name resolution

Due to PEP 503 package requirements might be specified using normalized
name which won't be resolved by WorkingSet.

Signed-off-by: Łukasz Daniluk <625ac74d8d40937ab00bcb9d689feaac6003111d@gmail.com>

pypa/setuptools,pypa/setuptools,pypa/setuptools