update yapf to 0.27.0

Bug: 1074167
Change-Id: I9f0c1c8a1fa76d6bf2899000fd0b3665f7bf0994
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2174818Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Anthony Polito <apolito@google.com>

yapf

@@ -3,7 +3,7 @@
 # [VPYTHON:BEGIN]
 # wheel: <
 #   name: "infra/python/wheels/yapf-py2_py3"
-#   version: "version:0.24.0"
+#   version: "version:0.27.0"
 # >
 # wheel: <
 #   name: "infra/python/wheels/futures-py2_py3"