Lower initial interval & make backoff exponential
Lower initial interval & make backoff exponential

If multiplier is 1.0, the backoff will not be exponential (default is
1.5).

Because we are starting with a lower interval, we can fit a couple of
retries within the 1s timeout that our integration tests are specifying.

[#131000981]

Signed-off-by: Zhou Yu <7f3430145af357a9fd7cb1a2d072f9b26e6234cb@pivotal.io>

pivotal-cf/cf-rabbitmq-release,pivotal-cf/cf-rabbitmq-release,pivotal-cf/cf-rabbitmq-release,pivotal-cf/cf-rabbitmq-release