deploy_flow_version: version requires int, but does not properly handle a passed in string

[cgmckeever]

If calling nipyapi.versioning.deploy_flow_version with a version that is a string, you get the following error. Would be nice for the method to int() for you ... maybe?

Validating Flow: ingest:6
Traceback (most recent call last):
  File "staging-manager.py", line 412, in <module>
    version=flow_version)
  File "/usr/local/lib/python3.7/dist-packages/nipyapi/versioning.py", line 740, in deploy_flow_version
    .format(str(version), flow_id, bucket_id, reg_client_id)
ValueError: Could not find Version [6] for Flow [00c7a05e-a9c4-48] in Bucket [ee44c97a-fb11-4873-] on Registry Client [848fed9e-0178]