CBIDXT-107: example script to add / delete buckets.

Change-Id: I3150838c9fdc4ea03cf7d400d3708df6e86e0b68
Reviewed-on: http://review.couchbase.org/40789
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Tested-by: Pratap Chakravarthy <prataprc@couchbase.com>