[Command] Don't run setup if needed for `pod setup`.

This lead to a double execution of setup if the automatic setup triggered.

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 [CocoaPods](https://github.com/CocoaPods/CocoaPods/compare/0.14.0...master)
 
+###### Bug fixes
+- In certain conditions pod setup would execute twice.
+- The git cache now is updated if a branch is not found
+  [#514](https://github.com/CocoaPods/CocoaPods/issues/514)
+
 ## 0.14.0
 
 [CocoaPods](https://github.com/CocoaPods/CocoaPods/compare/0.14.0.rc2...0.14.0) • [Xcodeproj](https://github.com/CocoaPods/Xcodeproj/compare/0.3.2...0.3.3)

lib/cocoapods/command.rb

@@ -70,7 +70,7 @@ module Pod
 
     def self.run(*argv)
       sub_command = parse(*argv)
-      unless ENV['SKIP_SETUP']
+      unless sub_command.is_a?(Setup) || ENV['SKIP_SETUP']
         Setup.new(ARGV.new).run_if_needed
       end
       sub_command.run