recommend to use buildout v1.7.0

2.0.0 won't work if you have old version of setuptools, older
packages are more isolated.

Change-Id: I461e3563593731b181799e9b77822401a8f8d9b9
Reviewed-on: http://review.couchbase.org/24549
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>