Add missing imports from typing (#933)

stdlib/3.4/pathlib.pyi

@@ -1,6 +1,6 @@
 # Stubs for pathlib (Python 3.4)
 
-from typing import Any, Generator, IO, Optional, Sequence, Tuple, Type, TypeVar, Union
+from typing import Any, Generator, IO, Optional, Sequence, Tuple, Type, TypeVar, Union, List
 import os
 import sys
 

stdlib/3/dis.pyi

@@ -1,4 +1,4 @@
-from typing import List, Union, Iterator, Tuple, Optional, Any, IO, NamedTuple
+from typing import List, Union, Iterator, Tuple, Optional, Any, IO, NamedTuple, Dict
 
 from opcode import (hasconst, hasname, hasjrel, hasjabs, haslocal, hascompare,
                     hasfree, hasnargs, cmp_op, opname, opmap, HAVE_ARGUMENT,