add (overwrite with) mypy stubs, if available

stdlib/2.7/pipes.pyi

@@ -0,0 +1,13 @@
+from typing import Any, IO
+
+class Template:
+    def __init__(self) -> None: ...
+    def reset(self) -> None: ...
+    def clone(self) -> Template: ...
+    def debug(flag: bool) -> None: ...
+    def append(cmd: str, kind: str) -> None: ...
+    def prepend(cmd: str, kind: str) -> None: ...
+    def open(file: str, mode: str) -> IO[Any]: ...
+    def copy(infile: str, outfile: str) -> None: ...
+
+def quote(s: str) -> str: ...