Release v2.1.18 - 2015-08-31

Tag release v2.1.18

References:
#793, #890, #898, #901, #910, #912

• Feature - Aws::EC2 - Launch Amazon EC2 Spot instances that have the lowest
  price per unit of capacity using the updated RequestSpotFleet API. Define and
  set target capacity in any unit including instances, vCPUs, memory, storage,
  or network throughput. You can specify how much each instance type is worth to
  your application, and automatically adjust your bid price for each type. This
  enables you to bid on multiple instance types in a single request and
  provision cost-effective capacity, regardless of instance type.

• Feature - Aws::ElasticLoadBalancing - Added a waiter that will poll
  until an instance has been deregistered.

  See related GitHub issue #793.

• Issue - Aws::EC2 - Added a missing #load method for
  Aws::EC2::NetworkInterfaceAssociation.

  See related GitHub issue #890.

• Issue - Retries - No longer retrying non-networking errors generated during
  HTTP handling.

  See related GitHub issue #912.