adds if case to publish either to pypi or testpypi

added alpha version for testing

Build from OAS 6.3.0 (XeroAPI#153)

* Build from OAS 6.3.0

Build from OAS 6.3.0 (XeroAPI#153)

* Build from OAS 6.3.0

Merge pull request XeroAPI#144 from XeroAPI/OAS-6.2.0-Xero-python

Build from OAS 6.2.0

Merge pull request XeroAPI#141 from XeroAPI/OAS-6.1.1-xero-python

Build from OAS 6.1.1

Merge pull request XeroAPI#139 from XeroAPI/xero-python-6.0.0

adds ultimate subplans

Bump version to 5.0.0 (XeroAPI#136)

Bump version to 5.0.0

build from oas 4.0.0 (XeroAPI#134)

Merge pull request XeroAPI#130 from XeroAPI/xero-python-3.0.0

Build from OAS 3.0.3