CBLT-202:  when you tell maven which pom file to use, it assumes project.build.directory to be the directory containing it.

Change-Id: I877727c45c5eae92a13ca2f5ae0bf8d841618348
Reviewed-on: http://review.couchbase.org/34718
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>