Test pagination against unchanging exact paginated resource.

Spec was based on changing data in a real repo. Changed to use paginated
search results with 3 fixed results so the test is easily repeatable
without changes.

Remove unused cassette.
Refreshed all cassettes.
Include license in README

Closes #422
Closes #423
Merge pull request #426 from joeyw/modify-pagination-spec

Test pagination against unchanging exact paginated resource.