* ResponseWriter wrapper to get status code
For our metrics, we need the status code returned by a request
so this wrapper includes a new method StatusCode() that includes
the desired code
* Shadow the responsewriter variable in the handlers
In order to avoid confusion to people deciding what variable to use.
I've also changed the tests to reflect this change and added a new
one that checks the Flush method works
* MM-16543 Add mocking for einterfaces packages
* MM-16543 Fix Elasticsearch only returning one page of results
* Remove license checks for einterface mocks
