Sync typeshed (#6007)

JukkaL · web-flow · commit a64c0a7734c2 · 2018-12-04T18:47:29.000Z
In particular, this includes python/typeshed#2670 that includes a change needed for improved TypedDict method support.
diff --git a/mypy/typeshed b/mypy/typeshed
@@ -1 +1 @@
-Subproject commit de50614957f3f599a6abe403d5508e9c53f8ad21
+Subproject commit c8890b0f930c1a8db45c9a2cd93540cb1aa1b0de
