Merge branch 'workaround_pypy_repr_recursion_error' into 'master'

Work around RecursionError in EntryPoint.__repr__ in pypy

See merge request pycqa/flake8!389

src/flake8/plugins/manager.py

@@ -41,7 +41,7 @@ class Plugin(object):
     def __repr__(self):  # type: () -> str
         """Provide an easy to read description of the current plugin."""
         return 'Plugin(name="{0}", entry_point="{1}")'.format(
-            self.name, self.entry_point
+            self.name, self.entry_point.value
         )
 
     def to_dictionary(self):