AMPforWP - AMP for WooCommerce 3.4

* Feature Added:
* Added Compatibility with Product Variation Table for WooCommerce Plugin.
* Added Compatibility with Advanced Woo Labels Plugin.
* Bugs Fixed:
* Resolved the issue of State field not working in the checkout page.
* Resolved the issue of Display number of Products option not working.

* Bug Fixed:
* Resolved the issue of Product page showing 404 error when we change the Product category base.

* Resolved the issue of flat rate not updating on checkout page.