WooCommerce Social Login 2.15.1

* Dev - Add filter to toggle loading of frontend scripts in the footer instead of head of the document page
* Misc - Add support for WooCommerce 3.5

* Tweak - Allow getting the user email address when signing up using a Twitter account (requires additional permissions)
* Tweak - Update the Twitter callback URL example for Twitter's new app requirements
* Misc - Drop support for PHP 5.2: PHP 5.3 is now the minimum supported version
* Misc - Upgrade HybridAuth authentication library to v2.11.0

* Fix - Ensure users are able to log in via VK without errors
* Fix - Additional fix for users registering in with non-ASCII usernames
* Fix - Ensure callback/redirect URIs displayed in the admin in sites that use SSL are prepended with HTTPS rather than HTTP by default
* Localization - Added Japanese translation provided by Hiro.M
* Localization - Updated Italian translation