Changed version to 1.5.1

Author: SteliyanH

SKCache.podspec

@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'SKCache'
-  s.version          = '1.5.0'
+  s.version          = '1.5.1'
   s.summary          = 'A caching libary to allow storing each possible type in Swift'
 
 # This description is used to generate tags and improve search results.