Merge branch 'fix-incorrect-pip-version'

vendor/pip-pop/pip-diff

@@ -12,11 +12,12 @@ Options:
 """
 import os
 from docopt import docopt
-from pip.index import PackageFinder
 from pip._vendor.requests import session
 try:  # for pip >= 10
+    from pip._internal.index import PackageFinder
     from pip._internal.req import parse_requirements
 except ImportError:  # for pip <= 9.0.3
+    from pip.index import PackageFinder
     from pip.req import parse_requirements
 
 requests = session()