Add support for ResourcesRequest to v4

[ismarc]

This adds support for the ResourcesRequest calls to v4 conjur
servers

What does this PR do?

• Adds support for listing resources from v4 conjur instances
• https://conjur.docs.apiary.io/#reference/resource/listsearch/list-or-search-for-resources covers the api for v4 for this endpoint. These changes don't fully implement path or path_text, but does implement kind, search, limit and offset

Checklists

Change log

• The CHANGELOG has been updated, or
• This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• This PR includes new unit and integration tests to go with the code changes, or
• The changes in this PR do not require tests

Documentation

• Docs (e.g. READMEs) were updated in this PR, and/or there is a follow-on issue to update docs, or
• This PR does not require updating any documentation

[izgeri]

@ismarc what is the use case for this going forward? We are announcing v4 deprecation in the next release (see #102) and will remove v4 support soon (though we can maintain it in a branch). Is there a time horizon when you won't still be using this? Are you consuming it as a dependency of another solution (like Summon)?

[ismarc]

@ismarc what is the use case for this going forward? We are announcing v4 deprecation in the next release (see #102) and will remove v4 support soon (though we can maintain it in a branch). Is there a time horizon when you won't still be using this? Are you consuming it as a dependency of another solution (like Summon)?

We need to sync data from conjurops v4 to conjurops v5, and during the transition period will need to regularly be syncing variables. This change lets us enumerate the accessible variables in a v4 instance via the resource listing.

So long as there's a single version that has the support included, we can reference that version.

[izgeri]

this probably needs a rebase against master before it can be merged - see the failing build (recent PR fixed it)

[izgeri]

Suggested change

	- ResourcesRequest is now supported for v4 conjur instances.
	- ResourcesRequest is now supported for Conjur Enterprise v4.
	[PR cyberark/conjur-api-go#106](https://github.com/cyberark/conjur-api-go/pull/106)

I am not sure whether it's worth including this since our next release soon will deprecate v4, so I'd also be ok with deleting it. up to you