fixed authentication issue

garminexport/garminclient.py

@@ -142,7 +142,11 @@ class GarminClient(object):
     def _validate_auth_ticket(self, validation_url):
         log.debug("validating authentication ticket ...")
         response = self.session.get(validation_url, allow_redirects=True)
-        if not response.status_code == 200:
+        if response.status_code == 200 or response.status_code == 404:
+            # for some reason a 404 response code can also denote a
+            # successful auth ticket validation
+            return
+            
         raise Exception(
             u"failed to validate authentication ticket: {}:\n{}".format(
                 response.status_code, response.text))