Bug 1384517 - Exclude testing/marionette/doc from linting; r=automatedtester

It also lists directories instead of globbing all files.

MozReview-Commit-ID: ApxmKVfEWTz

--HG--
extra : rebase_source : aca824c543e4a32499c6faa7593b3f18dddbe69c

.eslintignore

@@ -300,8 +300,9 @@ services/sync/services-sync.js
 testing/marionette/test_*.js
 testing/marionette/atom.js
 testing/marionette/legacyaction.js
-testing/marionette/client/**
-testing/marionette/harness/**
+testing/marionette/client
+testing/marionette/doc
+testing/marionette/harness
 
 # other testing/ exclusions
 testing/mochitest/**