Auto Retry deploy failures 3 times on travis

When a deploy fails hatchet will now retry a deploy HATCHET_RETRIES times before raising an error. This mitigates ghosts in the machine and makes the test suite's red/green status more truthy.
Merge pull request #102 from heroku/schneems/retry-hatchet-deploy-failures

Auto Retry deploy failures 3 times on travis
Add custom binary installation