WooCommerce Smart Coupons 8.20.1

* Fix: Store Credit not applying discount on manual renewal (WooCommerce Subscriptions)

* New: Single usage coupon for new user only
* New: Manage number of characters in auto generated coupon code
* New: Rename "Store Credit/ Gift Certificate"
* Fix: Import notice not showing when importing coupons in bulk
* Fix: Incompatibility with PHP 7 which resulted in store credit not deducting on order placement
* Fix: Not showing "Free shipping coupons"
* Fix: Coupon codes having spaces not working when applied by 1-click, showing message "Coupon does not exists"
* Fix: Formatting (HTML encoding) to coupon code causing incorrect linking of the coupon to the product
* Fix: Fallback for text domain which was causing fatal error in some cases
* Fix: Duplicate deduction from store credit [TaxJar]
* Fix: Incorrect discount calculation by store credit [AvaTax]
* Fix: Store credit coupon is not being applied correctly when a Mix and Match product is in the cart [Mix and Match product] IS#80
* Tweak: UI improvements in settings for Smart Coupons labels
* Tweak: Tool to clear cache
* Tweak: Better handling of Smart Coupons cache
* Tweak: Clear cache on deactivation
* Update: sample.csv file
* Update: POT File

* New: WordPress Coding Standard
* Fix: Link for Smart Coupons settings, which appears in admin notice, pointing to wrong page
* Fix: Store credit of 0 is visible on cart/checkout page
* Fix: Setting 'Apply before tax' not working for orders created manually from backend
* Fix: Checkbox 'Send coupons on renewals' doesn't hide even if there are no coupons linked
* Fix: Checkbox 'Apply before tax' remains checked on checking the checkbox 'Use store credit applied in first subscription...'
* Fix: When multiple store credits were applied from backend then removal of any one store credit was restoring balance to all other store credits
* Update: POT File