Add tests around inconsistent work counts

Issues CrossRef/rest-api-doc#304 and CrossRef/rest-api-doc#324 report consistency problems with works counts across a number of endpoints. This commit adds tests to verify data returned from those endpoints and specifically to make sure work counts across endpoints are consistent.

As part of this commit I also made a change to make sure the :items collection asserted against during testing was always in a deterministic state. This is why there are some changes to dev-resources that might not be expected.

I also needed to mock out get-member-list and get-prefix-info to return member and prefix info of a known state.