Update Jackson to v2.9.5 (#61)
Update Jackson to v2.9.5 (#61)

Mitigates security vulnerabilities in versions prior to 2.9.5.

Addresses:
* https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-5968
* https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7489
honeybadger-io/honeybadger-java