Fix BigInt export (#1456)

Author: erikwrede

graphene/__init__.py

@@ -13,6 +13,7 @@
     UUID,
     Argument,
     Base64,
+    BigInt,
     Boolean,
     Context,
     Date,
@@ -50,6 +51,7 @@
     "__version__",
     "Argument",
     "Base64",
+    "BigInt",
     "Boolean",
     "ClientIDMutation",
     "Connection",

graphene/types/__init__.py

@@ -15,7 +15,7 @@
 from .json import JSONString
 from .mutation import Mutation
 from .objecttype import ObjectType
-from .scalars import ID, Boolean, Float, Int, Scalar, String
+from .scalars import ID, BigInt, Boolean, Float, Int, Scalar, String
 from .schema import Schema
 from .structures import List, NonNull
 from .union import Union
@@ -24,6 +24,7 @@
 __all__ = [
     "Argument",
     "Base64",
+    "BigInt",
     "Boolean",
     "Context",
     "Date",