add (overwrite with) mypy stubs, if available

stdlib/3/types.pyi

@@ -0,0 +1,19 @@
+# Stubs for types
+
+# TODO this is work in progress
+
+from typing import Any
+
+class ModuleType:
+    __name__ = ... # type: str
+    __file__ = ... # type: str
+    def __init__(self, name: str, doc: Any) -> None: ...
+
+class MethodType: ...
+class BuiltinMethodType: ...
+
+class TracebackType:
+    tb_frame = ... # type: Any
+    tb_lasti = ... # type: int
+    tb_lineno = ... # type: int
+    tb_next = ... # type: Any