Expose configuration options for instance principals about oci-go-sdk

[eginez]

@drewwells quick question on the MockServer idea, would it behave as the opc metadata server?. We would have to configure the InstancePrincipalConfigurationProvider to somehow talk to such server as well correct?

Would it suffice to make a InstancePrincipalsConfigurationProvider configurable in such a way that you can pass arbitrary certificates?. Further if you would like to mock the certificate gathering then you can implement your own mockedConfigurationProvider and pass that to your clients as part of your unit tests, that would allow you to isolate your code. Maybe I am missing something?

[eginez]

Hey @drewwells we published changes that will allow you to create an InstancePrincipals with harcoded credentials. This should address your concerns, if that is not the case feel free to reopen the issue

[drewwells]

This looks great, thanks!