almost production ready

Releasing mamiya v0.1.1

Since we, Cookpad is using this on production ,
I'm planning to release this as 1.0.0 later, unless any problem found.

Bug fixes

• When mamiya client status (application) try to sho agent name list, but
  server name is shown as empty string 💬
• mamiya client deploy command might ignore unparticipants agent 😨
  • unparticipants agent might be untouched on deploy
• wording fixes 📝

Others

• now using aws-sdk-core.gem>=2.0.0 (was =2.0.0.rc15) ☝️
  • congrats AWS team for releasing stable version! 🎉