Support calling internal API using HTTPS

Closes #179

See merge request gitlab-org/gitlab-shell!297

Print keys in list-keys command

See merge request gitlab-org/gitlab-shell!198

Support calling internal api using HTTP

See merge request gitlab-org/gitlab-shell!295

Add doc about Go migration feature flags

See merge request gitlab-org/gitlab-shell!296

Correctly determine the root directory for gitlab-shell

See merge request gitlab-org/gitlab-shell!294

Credit to https://gitlab.com/ejiek for spotting this one.

Add Ash as a maintainer for gitlab-shell

Closes #170

See merge request gitlab-org/gitlab-shell!260

Release v9.0.0

See merge request gitlab-org/gitlab-shell!293

Merge branch '9217-warn-on-git-fetch-over-ssh-if-the-secondary-is-lagging-the-primary' into 'master'

Display console messages, if available

See merge request gitlab-org/gitlab-shell!287

Using ConsoleHelper::write_stderr

.write_stderr
.format_for_stderr

Merge branch '182-lib-gitlab_net-rb-37-in-check_access-uninitialized-constant-gitlabnet-gitaccessstatus-nameerror' into 'master'

Explicitly include gitlab_access_status.rb

Closes #182

See merge request gitlab-org/gitlab-shell!292

Remove hooks, they belong to Gitaly now

See merge request gitlab-org/gitlab-shell!291

Display post receive warnings from Rails

See merge request gitlab-org/gitlab-shell!288

Add pry gem to allow easy debugging

See merge request gitlab-org/gitlab-shell!289

print_warnings is now using that method in order to print a large
formatted warning message, so renaming the method to be less tied to
the broadcast message functionality.

Warnings are printed using the same method that prints broadcast
messages. This ensures that whatever warnings are returned will be
displayed correctly.

Provide go implementation for 2fa_recovery_codes command

See merge request gitlab-org/gitlab-shell!285

Better testing for JSON deserialisation

See merge request gitlab-org/gitlab-shell!282

Adds tests to ensure that JSON deserialisation from program arguments
takes place. This was a testing blind spot, which led to a brief
regression:

https://gitlab.com/gitlab-org/gitlab-shell/merge_requests/280

Call gitlab "/internal/discover" from go

Closes #175

See merge request gitlab-org/gitlab-shell!283

The reporter struct can be used for passing around and reporting to
the io.Writer of choice.

This allows gitlab-shell to be called with an argument of the format
`key-123` or `username-name`.

When called in this way, `gitlab-shell` will call the GitLab internal
API. If the API responds with user information, it will print a
welcome message including the username.

If the API responds with a successful but empty response, gitlab-shell
will print a welcome message for an anonymous user.

If the API response includes an error message in JSON, this message
will be printed to stderr.

If the API call fails, an error message including the status code will
be printed to stderr.

Get secret from config

See merge request gitlab-org/gitlab-shell!284

This adds parsing if the `secret_file` from YAML. And reads the
contents of the configured file.

If no file is configured, we fall back to the `.gitlab_shell_secret`
in the root dir of the configuration.

If the configured path does not start with a `/` we start looking for
the file relative to the root dir of the configuration.