Update GitLab Exporter to 7.0.1

Related to https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/5179

Upgrade Go image, and thus related binaries in our containers to make
use of Golang 1.13.9, as 1.12.x is EOL.

Update PG to 11.7, matching upstream stable/postgresql charts container

Relates to https://gitlab.com/gitlab-org/charts/gitlab/-/issues/1848

- Bump `gitlab-mail_room` version

* `omnibus-gitlab` utilizes `GITALY_SERVER_VERSION`
* This change makes external coding a tad easier by using a variable
that is consistent between the two projects

Gitaly now supports new minimum version of Git because it depends on the new features from it, please see https://gitlab.com/gitlab-org/gitaly/merge_requests/1653

Part of: https://gitlab.com/gitlab-org/gitaly/issues/2170

Gitaly now supports new minimum version of Git because it depends on the new features from it, please see https://gitlab.com/gitlab-org/gitaly/merge_requests/1653

Part of: https://gitlab.com/gitlab-org/gitaly/issues/2170

Signed-off-by: Balasankar "Balu" C <balasankar@gitlab.com>

Closes https://gitlab.com/gitlab-org/charts/gitlab/issues/1569

Update the Go version to 1.12.13, latst of the 1.12 minors as of
2019-10-31

https://golang.org/doc/devel/release.html#go1.12.minor

This brings in a single logging change to track down 0-byte uploads:
https://gitlab.com/gitlab-org/container-registry/merge_requests/8

Update the CNG to Alpine 3.10
- cfssl-self-sign
- alpine-certificates
    - Update the ca-certificates contained

v2.7.3-gitlab updates the storage driver to use the latest Google SDK:
https://gitlab.com/gitlab-org/container-registry/merge_requests/2

v2.7.4-gitlab fixes an issues with v2.7.3-gitlab with non-default
Google credentials:
https://gitlab.com/gitlab-org/container-registry/merge_requests/7

This registry upgrade hopefully will fix 0-byte upload issues:
https://github.com/googleapis/google-cloud-go/issues/746

This brings in the MD5 checksum changes in
https://gitlab.com/gitlab-org/container-registry/merge_requests/1.

Note this also uses https://gitlab.com/gitlab-org/container-registry,
instead of https://github.com/docker/distribution.

Closes https://gitlab.com/gitlab-org/distribution/team-tasks/issues/499

It will usually be set to a specific version by release-tools. We should behave consistently when it isn't.