Goployer should support termination policy

Currently goployer does not support termination policy setting. Now all autoscaling group is supposed to use Default termination policy.

termination_policies option could be suitable for this configuration and this should be regional based. (per autoscaling group)

regions:
  - region: ap-northeast-2
    termination_policies: 
      - Default
      - OldestInstance

If termination_policies is not specified, then it should include Default only.

DevopsArtFactory / goployer