Initial support for basic WooCommerce integration

can export products to WooCommerce, plus maintain local cache, and track Woo ID
for each rattail product

CHANGELOG.md

@@ -0,0 +1,10 @@
+
+# Changelog
+All notable changes to rattail-woocommerce will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [0.1.0] - ??
+### Added
+- Initial version.