MB-12251: Remove rebalance tests

The rebalance tests for the spatial views should be rewritten with
the new testrunner API. Hence I'm removing the old ones.

Change-Id: I7eeb54900b7d21e1dc27793829a097962e1a9947
Reviewed-on: http://review.couchbase.org/43852
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>
MB-12251: Comment out not yet working tests

Change-Id: Ibe966fd4477a33c3df3b77bdd6299f779bf9417a
Reviewed-on: http://review.couchbase.org/43853
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>
MB-12251: Use default prefix

Instead of using a random prefix for the documents, use `doc` as the
default prefix. This way every run of a test is same which makes
debugging issues way simpler.

Change-Id: Ia35ddf9ed78f160326cf7d2cbc381ae9e2712da0
Reviewed-on: http://review.couchbase.org/43854
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>