MB-10736: Install lib/python/couchstore.py

Change-Id: Ie7c81fdb55a44996e0451c8f41715f1603da04b4
Reviewed-on: http://review.couchbase.org/35487
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>