pydrive2: require six >= 1.13.0

iterative/PyDrive2#56

Author: efiop

setup.py

@@ -88,7 +88,7 @@ def run(self):
 # Extra dependencies for remote integrations
 
 gs = ["google-cloud-storage==1.19.0"]
-gdrive = ["pydrive2>=1.6.1"]
+gdrive = ["pydrive2>=1.6.1", "six >= 1.13.0"]
 s3 = ["boto3>=1.9.201"]
 azure = ["azure-storage-blob>=12.0", "knack"]
 oss = ["oss2==2.6.1"]