5.5.2

Enhancements: new license tab for license product page
Enhancements: new deactivation functionality for front end user (woocommerce page)
Enhancements: new deactivation functionality for admin page
Enhancements: added slm_billing_interval and slm_billing_length params to api
Bugs: item_reference param was preventing a license key from activation, it was returning invalid license key.