YITH WooCommerce Stripe Premium 3.20.0

* New: WooCommerce 3.4.0 support
* New: WordPress 4.9.6 support
* New: updated plugin fw
* New: GDPR compliance
* New: Stripe library 6.7.1 (Requires API update on Stripe Dashboard)
* New: trial period is now added only when Subscription Product has trial set
* New: added billing and shipping information on Stripe Checkout payment mode
* New: added Hosted mode, similar to free version
* Tweak: added description to renew charges after successful charge webhook
* Tweak: improved customer handling when registering cards
* Tweak: moved notify_failed_renewal to avoid issues when adding a new card from My Account endpoint
* Fix: plan creation, for newer version of API
* Fix: now subscription is cancelled after end date
* Fix: improved js to avoid implict conversions
* Dev: added yith_wcstripe_plan_trial_period filter
* Dev: added filter yith_wcstripe_gateway_enabled to programmatically enable/disable Stripe Gateway
* Dev: added filter yith_wcstripe_gateway_id to let developers filter gateway ID (Use this filter at your own risk; after filtering gateway ID you will need to configure gateway again)

New: WooCommerce 3.3.1 support
New: WordPress 4.9.4 support
New: updated Stripe library to 6.0 revision
New: updated plugin-fw library

• New: WooCommerce 3.2.6 support
• New: updated plugin-fw to version 3.0
• New: updated Stripe library to 5.8 revision
• Tweak: added check over save_cards flag before token creation; this way cards won't be actually saved if admin disable related option
• Fix: check on captured flag on payment_complete
• Fix: stripe script not being loaded in Add Payment Method page
• Fix: token error when remember card functionality is disabled
• Fix: trial start/end time when pausing/resuming subscriptions
• Dev: added yith_wcstripe_subscription_amount to let third party plugin to change plan amount
• Dev: added yith_wcstripe_card_number_dots filter to let dev change "dots" in cc number
• Dev: added filters to change default CC form labels
• Dev: added yith_wcstripe_environment filter
• Dev: added yith_wcstripe_metadata filter to let third party developers change metadata sent to Stripe servers