update homepage url

StretchKit.podspec

@@ -3,7 +3,7 @@ Pod::Spec.new do |s|
   s.version          = '0.3.2'
   s.summary          = 'Swift bindings for the Stretch layout engine.'
   s.description      = "A high performance & cross-platform layout engine."
-  s.homepage         = 'https://visly.app/stretch'
+  s.homepage         = 'https://vislyhq.github.io/stretch/'
   s.license          = { :type => 'MIT', :file => 'LICENSE' }
   s.author           = { 'Visly Inc.' => '[email protected]' }
   s.source           = { :git => 'https://github.com/vislyhq/stretch.git', :tag => s.version.to_s }