Look for field 'detail' in error message. (#739)

Author: busunkim96

googleapiclient/errors.py

@@ -52,6 +52,8 @@ def _get_reason(self):
         reason = data['error']['message']
         if 'details' in data['error']:
             self.error_details = data['error']['details']
+        elif 'detail' in data['error']:
+            self.error_details = data['error']['detail']
       elif isinstance(data, list) and len(data) > 0:
         first_error = data[0]
         reason = first_error['error']['message']