Find .egg-info in zipimport too

Fixes #2489

changelog.d/2489.change.rst

+``pkg_resources`` behavior for zipimport now matches the regular behavior, and finds
+``.egg-info`` (previoulsy would only find ``.dist-info``) -- by :user:`thatch`

pkg_resources/__init__.py

@@ -1978,12 +1978,13 @@ def find_eggs_in_zip(importer, path_item, only=False):
         # don't yield nested distros
         return
     for subitem in metadata.resource_listdir(''):
+        lower = subitem.lower()
         if _is_egg_path(subitem):
             subpath = os.path.join(path_item, subitem)
             dists = find_eggs_in_zip(zipimport.zipimporter(subpath), subpath)
             for dist in dists:
                 yield dist
-        elif subitem.lower().endswith('.dist-info'):
+        elif any(map(lower.endswith, ('.dist-info', '.egg-info'))):
             subpath = os.path.join(path_item, subitem)
             submeta = EggMetadata(zipimport.zipimporter(subpath))
             submeta.egg_info = subpath