Update podspec to version 1.6.1-beta.2 (beta.1 is already taken)

Author: mindgraffiti

WPMediaPicker.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = "WPMediaPicker"
-  s.version          = "1.6.1-beta.1"
+  s.version          = "1.6.1-beta.2"
   s.summary          = "WPMediaPicker is an iOS controller that allows capture and picking of media assets."
   s.description      = <<-DESC
                        WPMediaPicker is an iOS controller that allows capture and picking of media assets.