update_engine: Add CPPLINT.cfg

Adds CPPLINT.cfg which disables build/include_order and
build/include_guard and enables build/alpha_order.

BUG=chromium:753892
Test: repo upload --cbr .

Change-Id: I3be65e3be2670948de5e765d50c0a032ecbd5f81
Reviewed-on: https://chromium-review.googlesource.com/630478
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit eb875805d8b897913c190ffb0bf87b275037ac2a)
diff --git a/CPPLINT.cfg b/CPPLINT.cfg
new file mode 100644
index 0000000..3dd0f35
--- /dev/null
+++ b/CPPLINT.cfg
@@ -0,0 +1,3 @@
+# This should be kept in sync with platform2/CPPLINT.cfg
+set noparent
+filter=-build/include_order,+build/include_alpha,-build/header_guard