Use Producer instead of ProducerPool
Use Producer instead of ProducerPool

* Connection and channel management is possible with Producer. ProducerPool
  takes over the management leading to shadow ConnectionPool and presumably
  connections to which we get no access. Producer keeps the management under
  our control.
* Explicitly use the 'round-robin' strategy. Although a default making it
  explicit to avoid any ambiguiity and impact due to changing defaults.

tonybaloney/st2,lakshmi-kannan/st2,Plexxi/st2,nzlosh/st2,peak6/st2,pixelrebel/st2,StackStorm/st2,StackStorm/st2,armab/st2,punalpatel/st2,emedvedev/st2,Itxaka/st2,Plexxi/st2,dennybaa/st2,tonybaloney/st2,nzlosh/st2,dennybaa/st2,lakshmi-kannan/st2,alfasin/st2,peak6/st2,dennybaa/st2,peak6/st2,punalpatel/st2,Plexxi/st2,armab/st2,nzlosh/st2,nzlosh/st2,armab/st2,Plexxi/st2,StackStorm/st2,emedvedev/st2,lakshmi-kannan/st2,tonybaloney/st2,punalpatel/st2,emedvedev/st2,alfasin/st2,Itxaka/st2,pixelrebel/st2,Itxaka/st2,pixelrebel/st2,alfasin/st2,StackStorm/st2