Fix failing spec caused by now invalid test double
Implement a SearchResultsCollection entity.
Modify GoogleCustomSearchResponseMapper to handle a paginated response.

Refactor the spec a little too.
Modify GoogleCustomSearchEngine to use modified mapper.

Small amount of tweaking to spec.
Add attributes to SearchResultCollection to hold metadata for paginated results.
Modify Searcher to allocate pagination metadata from the repository to the collection entity.
Modify GoogleCustomSearchEngine to request paginated results.
Modify Searcher to accept a page to select paginated results.
Add a bunch of helper methods to SearchResultCollection.
Add pagination scenario
Move GoogleCustomSearchEngineResponseMapper to GoogleCustomSearchEngine::ResponseMapper.
Add dedicated mapper class for Google CSE response items.
Namespace specs to shorten the line length of some expectations.
WIP - Add actual pagination functionality to site.