Flyouts - Off Canvas Custom Content for WordPress 1.4.2

Update: CMB2 Library to v2.7.0
Update: Updater script to v1.4
Fix: In some cases, a PHP error would throw checking for the Flyout menu.
Fix: In some cases, mobile webkit browsers would crash if using over 20 active flyouts due to using the -webkit-overflow-scrolling CSS property.

Fix: Submenu icon indicators were missed in replacing to SVG from previous update.

-Update CMB2 Library to v2.4.2
-Update Plugin updater library to v4.4 and will check via HTTPS.
-Replace font icons with SVG
-Minor CSS adjustments