[BUG]: pyZscaler doesn't support non-production clouds

[mitchos]

Describe the bug

A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Use pyZscaler with any other non-production cloud (e.g. beta, FeVa)
2. pyZscaler has no functionality to permit this

Expected behavior

pyZscaler should be able to provide an easy interface for the standard production clouds that would cover most use-cases and also accept beta, FeVa and any other arbitrary URL (e.g. internal testing) for a Zscaler tenancy. Support should be available for this across all product modules.