Fix undefined tokenProvider when access token is provided.

[Gilighost]

Changes

When using the ManagementClient, tokenProvider is expected to be a member of the options object which is passed to various Managers such as the JobsManager. However, when the ManagementClient is configured with only a domain and a token, tokenProvider is not assigned to the options object which results in an error when a Manager attempts to access options.tokenProvider.getAccessToken because tokenProvider is undefined.

e.g. https://github.com/auth0/node-auth0/blob/master/src/management/JobsManager.js#L142

This PR moves the line which assigns the tokenProvider to the options object out of an if statement so that the assignment is performed on all code paths.

Testing

Test this by using the ManagementClient with an access token as specified in the docs.
https://auth0.github.io/node-auth0/module-management.ManagementClient.html

var ManagementClient = require('auth0').ManagementClient;
var auth0 = new ManagementClient({
  domain: '{YOUR_ACCOUNT}.auth0.com',
  token: '{YOUR_API_V2_TOKEN}'
});

Then attempt to use a method provided by the JobsManager. e.g. import users job

Previously, this would throw an error:

TypeError: Cannot read property 'getAccessToken' of undefined

But with this change, it should start the job as expected.

• This change adds unit test coverage
• This change adds integration test coverage

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All existing and new tests complete without errors

[davidpatrick]

Thanks @Gilighost