GLKit is deprecated. Consider migrating to MetalKit instead.

[Sevyls]

XCode 11.4 shows the following Deprecation warning for KVNProgress 2.3.5:

"GLKit is deprecated. Consider migrating to MetalKit instead."

MetalKit requires iOS 9.0+, so this change would change the minimum required iOS Version for KVNProgress to this.

I would like to investigate necessary changes, does someone know the key GLKit usages of KVNProgress ?