Fix for ApiKey configuration fields not working for the API functions (#52)

[TriggerAu]

Note: This fix is premised on an assumption that the ApiKey parameter in the Configuration object is meant to be an ApiToken from the management interface, based on the details in the management.yaml (more in the bug report).

If the fix should be to add an extra attribute called ApiToken to the Configuration object let me know and Ill adjust the PR

I kept the work in two commits:

• The openapi mustache template changes for the config and api calls
• The generated ps1 files

Changes

• ApiKey is now a string instead of a hashtable and takes the apiToken that is generated in the admin interface
• ApiKeyPrefix is now a string instead of a hashtable and defaults to SSWS
• The logic in the methods for ApiKey uses it in the Authorization portion of the request header for the api per the API docs: Authorization: SSWS {API Token}

The usage of this method is as below:

$Configuration = Get-OktaConfiguration
$Configuration.BaseUrl = 'https://myorg.okta.com'
$Configuration.ApiKey = 'myApiToken'
Invoke-OktaListUsers

the ApiKeyPrefix defaults to the SSWS value from the documentation

Issue #52

Other Note: Im not sure how the team maintain/ask contributors to adjust the version/build log, but if there is anything I can do to help in that regard just lemme know