use transport and bump retries

src/gam/auth/signjwt.py

@@ -73,8 +73,10 @@ class SignJwt(google.auth.crypt.Signer):
 
     def sign(self, message):
         ''' Call IAM Credentials SignJWT API to get our signed JWT '''
+        request = transport.create_request()
         try:
-            credentials, _ = google.auth.default(scopes='https://www.googleapis.com/auth/iam')
+            credentials, _ = google.auth.default(scopes='https://www.googleapis.com/auth/iam',
+                                                 request=request)
         except google.auth.exceptions.DefaultCredentialsError as e:
             controlflow.system_error_exit(2, e)
         httpObj = transport.AuthorizedHttp(

src/gam/transport.py

@@ -9,6 +9,8 @@ from gam.var import GC_TLS_MAX_VERSION
 from gam.var import GC_TLS_MIN_VERSION
 from gam.var import GC_Values
 
+# Bump default retries
+httplib2.RETRIES = 5
 
 def create_http(cache=None,
                 timeout=None,