Add dumb postCSS config file.

Author: nchevobbe

packages/devtools-reps/postcss.config.js

@@ -0,0 +1,6 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Dumb export so launchpad does not throw.
+module.exports = () => ({});