Bump version to 1.5.1
Bump version to 1.5.1

Change-Id: I7dd18975d2f8c558ddff5f0e3114cfb35b09ec9a
Reviewed-on: http://review.couchbase.org/78501
Reviewed-by: Mark Nunberg <dab05a0fe859c5cb93882b2a75a0d613501b07be@couchbase.com>
Tested-by: Mark Nunberg <dab05a0fe859c5cb93882b2a75a0d613501b07be@couchbase.com>
Reviewed-by: Subhashni Balakrishnan <7129c8e37b832c7bd362ff375532d24b98ef5162@gmail.com>

couchbase/CouchbaseMock,couchbase/CouchbaseMock