Add support for Pageflow 13

Author: tf

pageflow-before-after.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '~> 2.1'
 
-  spec.add_dependency 'pageflow', ['>= 0.11', '< 13']
+  spec.add_dependency 'pageflow', ['>= 0.11', '< 14']
   spec.add_dependency 'pageflow-public-i18n', '~> 1.8'
 
   spec.add_dependency 'jquery-ui-rails', '~> 5.0'