CBD-1438: Centos build script and Docker image for Sherlock builds

Change-Id: I9e05ab193ee0321d25dc110d237e5c5c1ba569a1
Reviewed-on: http://review.couchbase.org/42243
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>