Run yapf with vpython3

R=ehmaldonado@chromium.org

Bug: 1197346
Change-Id: Ifc56ff316954eaa3c532b212371de57f8884ff97
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2822446Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

yapf

-#!/usr/bin/env vpython
+#!/usr/bin/env vpython3
 
 # [VPYTHON:BEGIN]
 # wheel: <

yapf.bat

@@ -9,4 +9,4 @@ setlocal
 set PATH=%PATH%;%~dp0
 
 :: Defer control.
-vpython "%~dp0\yapf" %*
+vpython3 "%~dp0\yapf" %*