Allow user to use existing bucket with same name via fission storage service (#2275)
Allow user to use existing bucket with same name via fission storage service (#2275)

* If a bucket already exists with the same name, allow the user to use that one
* Abstracted create or get a storage container
* Check err when the con is empty and return container name with error
fission/fission,fission/fission,fission/fission,fission/fission