[Command::Push] Respect allow warnings option

Closes #835

CHANGELOG.md

@@ -10,6 +10,8 @@
 - Fixed and issue which prevent the inclusion of OTHER_CFLAGS and
   OTHER_CPLUSPLUSFLAGS  in the release builds of the Pods project.
 - Fixed `pod lint --local`
+- Fixed the `--allow-warnings` of `pod push`
+  [#835](https://github.com/CocoaPods/CocoaPods/issues/835)
 
 ###### Ancillary enhancements
 

lib/cocoapods/command/push.rb

@@ -63,6 +63,7 @@ module Pod
         UI.puts "\nValidating #{'spec'.pluralize(count)}".yellow
         podspec_files.each do |podspec|
           validator = Validator.new(podspec)
+          validator.only_errors = @allow_warnings
           begin
             validator.validate
           rescue Exception