* Upgrade go.mod file
* Upgrade travis file
* Run rm -rf vendor && go mod tidy && go mod vendor to upgrade vendor/modules.txt according to golang 1.14
* Upgrade golangci-lint version
gometalinter is broken @ HEAD, and I looked into why that was. During
that process, I remembered that we took the linting scripts from
skaffold, and found that in skaffold gometalinter was replaced with
GolangCI-Lint:
https://github.com/GoogleContainerTools/skaffold/pull/619
The change made linting in skaffold faster, so I figured instead of
fixing gometalinter it made more sense to remove it and replace it with
GolangCI-Lint for kaniko as well.
Ben Einaudi
Cole Wippern
Priya Wadhwa