This reverts merge request !17737

- only older ruby and activerecord support dropped

These warnings would show when running rspec:

```
warning: parser/current is loading parser/ruby23, which recognizes
warning: 2.3.5-compliant syntax, but you are running 2.3.6.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
```

Related PRs:

* https://github.com/whitequark/parser/pull/422
* https://github.com/mbj/unparser/pull/79

Related to gitaly#1060

Given 1.9 has issues we're aware of, for now we're locking to 1.8.
Closes gitlab-org/gitaly#1059 and will probably be removed if 1.10 is
tested an deemed ok.

Closes gitaly#1046

36847 - add changelog

26039 - add merge request id


26039 change due to lingust source file updates

Closes gitaly#985

Closes gitlab-org/omnibus-gitlab#3128

Gem is updated from 2.8 to 2.10. [changelog][1]

[1]: https://github.com/seattlerb/flay/blob/master/History.rdoc

Implements the client side for gitlab-org/gitaly#819. Which is a server
info command. This checks the server version and git binairy version on
the server.

A small UI was added for administrators, so they can check the status of
the Gitaly server. This is done for each storage the monolith knows.

Because of this commit, gitlab-org/gitlab-ce!15580 is now closed. That
MR removed the Git version too, but didn't replace it with anything.

Closes gitaly#979

Closes gitaly#967

Signed-off-by: NRémy Coutable <remy@rymai.me>

Closes gitaly#958

Signed-off-by: NRémy Coutable <remy@rymai.me>

Closes gitaly#946

Closes gitaly#929

Signed-off-by: NRémy Coutable <remy@rymai.me>