(#1515) - Add authentication headers on destroy

"Remove a pouch" tests were previously failing against
Cloudant databases. The root cause appears to be due
to authentication headers not being added to the DELETE
request correctly.

This patch adds the default headers (including authentication)
to the request and the test now passes.
(#1760) - Remove social buttons for now
(#1770) - Return status 'cancelled' when replication is cancelled
(#1773) - Intermittent allDocs error
(#113) - Run coverage tests and upload results