Use network specific hpcloud region-b providers

It has been suggested that we use fewer nodes per network:router
pairing in hpcloud region-b with nodepool. Test this by adding nodepool
providers for new network:router pairings. This will put up to 118 nodes
on each network:router of which we now have 5.

Change-Id: I126316e04554d044721ae1495a17d207e0de464a
Merge "Use network specific hpcloud region-b providers"