Updating success logic

Updating the definition of SUCCESS response code to be 200 OK or 201
Continue. Error is anything that isn't success. This helps flag
conditions like an unsuccessful update (return code 304) which the
library would have flagged as success earlier

lib/google/api_client/result.rb

@@ -79,13 +79,13 @@ module Google
       end
       
       ##
-      # Check if request failed
+      # Check if request failed - which is anything other than 200/201 OK
       #
       # @!attribute [r] error?
       # @return [TrueClass, FalseClass]
       #   true if result of operation is an error
       def error?
-        return self.response.status >= 400
+        return !self.success?
       end
 
       ##
@@ -95,7 +95,11 @@ module Google
       # @return [TrueClass, FalseClass]
       #   true if result of operation was successful
       def success?
-        return !self.error?
+        if self.response.status == 200 || self.response.status == 201
+          return true
+        else
+          return false
+        end
       end
       
       ##