Use SetUp() instead of SetUpTestCase

I came upon this problem when I started actually randomizing bootstrap
nodes. In this case we'd hang on a single connection for a long time - I
figured out that the previous test was failing over nodes and there was
nothing to restore them. Using SetUp runs before each test function
rather than SetUpTestCase which runs only before the class itself.

This makes things far quicker and more reliable.

Change-Id: I727cb8faba538a6515dfab41f934c6acebe367a5
Reviewed-on: http://review.couchbase.org/34021
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>