Hmt-escrow

* 299 Missed one place from previous PR where we log a warning instead of a debug

297 Use DEBUG level for retry transaction logs

* Allow funding escrow on behalf of a different HMT owner

- Adds improves retry with backoff

What's Changed
* Job.launch update to fail close
* Job.launch adds a parameter wait_on_failure to include waiting time before trying with a different credentials in multi-cred mode
* Updated readme to show Human's Bug Bounty

**Full Changelog**: https://github.com/humanprotocol/hmt-escrow/compare/0.9.4...0.9.5

What's Changed
* Fix version of `web3` to resolve BC breaks by spirit-q2 in https://github.com/humanprotocol/hmt-escrow/pull/281

New Contributors
* spirit-q2 made their first contribution in https://github.com/humanprotocol/hmt-escrow/pull/281

**Full Changelog**: https://github.com/humanprotocol/hmt-escrow/compare/0.9.3...0.9.4