support envoy 1.14.1

[hanshasselberg]

Since this is a new minor envoy version, it should only go into 1.8. With this PR we are officially dropping envoy 1.10.x support.

Checklist

• Run the full Envoy integration test using the new version:

make test-envoy-integ ENVOY_VERSIONS="1.14.1"

• In the correct release branch update the default ENVOY_VERSIONS value in run-tests.sh. It should contain the new version and the most recent point release of the 3 major versions before e.g. "1.9.1 1.8.0 1.11.2 1.12.0"
• Update the CI jobs in .circleci/config.yml. There are multiple jobs named envoy-integration-test-* where the oldest has a full definition while the others are aliases that just change the version number.
• Update the version numbers such that they match the new supported list.
• Update the list of envoy-integration-test-* jobs in the test-integrations workflow to match the new job names changes above.
• Update the supported versions list in the docs in website/source/connect/proxies/envoy.md
• Update the default envoy version of -envoy-version in command/connect/envoy/envoy.go and website/source/docs/commands/connect/envoy.html.md.erb
• Update the default envoy version in the golden master files in command/connect/envoy/testdata/*
• Create a PR for consul-k8s to update the default Envoy image to be the latest supported version. It's currently here: https://github.com/hashicorp/consul-k8s/blob/f75b6f559fae9f96667820796edd47c0c7a3824b/connect-inject/handler.go#L23 but probably worth checking the code base and updating this list if there are other references: Consul will support envoy 1.14.1 with Consul 1.8 consul-k8s#245
• Create PR for consul-helm to update the default Envoy image. Currently https://github.com/hashicorp/consul-helm/blob/master/values.yaml#L609 but again grep and sanity check: Consul will support envoy 1.14.1 with Consul 1.8 consul-helm#421
• Create an issue for Nomad to update the default Envoy docker image they use in their integration with a link to the PR and information about the version we will make the change in and the expected timeline for release: Consul will support envoy 1.14.4 with Consul 1.8 nomad#7665.

[dnephin]

LGTM

I re-ran the test-integrations workflow to see if the failure on 1.14.1 was a flake