[Snyk] Security upgrade ubuntu from trusty to trusty-20190515

[circleci-secops]

This PR was automatically created by Snyk using the credentials of a real user.

Keeping your Docker base image up-to-date means you’ll benefit from security fixes in the latest version of your chosen image.

Changes included in this PR

• contrib/builder/deb/ubuntu-trusty/Dockerfile

We recommend upgrading to ubuntu:trusty-20190515, as this image has only 292 known vulnerabilities. To do this, merge this pull request, then verify your application still works as expected.

Some of the most important vulnerabilities in your base image include:

Severity	Priority Score / 1000	Issue	Exploit Maturity
	536	Improper Check for Dropped Privileges SNYK-UBUNTU1404-BASH-542607	Mature
	829	Off-by-one Error SNYK-UBUNTU1404-SUDO-1065770	Mature
	686	Improper Privilege Management SNYK-UBUNTU1404-SUDO-3234995	Mature
	686	Improper Handling of Exceptional Conditions SNYK-UBUNTU1404-SUDO-473059	Mature
	536	Out-of-bounds Write SNYK-UBUNTU1404-SUDO-546522	Mature

---

Note: You are seeing this because you or someone else with access to this repository has authorized Snyk to open fix PRs.

For more information: 🧐 View latest project report

🛠 Adjust project settings

---

Learn how to fix vulnerabilities with free interactive lessons:

🦉 Improper Privilege Management