Small improvements

- refactor GitlabKey away
- fix Redis check output

See merge request !81

It is not nice to have both 'GitlabKeys' and 'GitlabKey'. We also do
not need GitlabKey to be a class when it has no state.

Improve authorized_keys check

The old check only looked if authorized_keys exists. With this change, we look
whether we can actually open the file for reading and writing. When this fails
we try to print useful diagnostic information.

See merge request !79

The old check only looked if authorized_keys exists. With this change, we look
whether we can actually open the file for reading and writing. When this fails
we try to print useful diagnostic information.

Manage authorized_keys permissions continuously

We can lazily create authorized_keys and set its permissions. This
adds negligible overhead and it allows us to remove a setup step from
GitLab both on source and in omnibus-gitlab.

See merge request !78

We can lazily create authorized_keys and set its permissions. This
adds negligible overhead and it allows us to remove a setup step from
GitLab both on source and in omnibus-gitlab.

Add command to move repositories between repository storages

Necessary for https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/533

/cc @pcarranza 

See merge request !71

Track ongoing pushes and reject mv-storage commands if there are push running (after waiting some time)

Merge branch '51-gitlab-project-s-fork_project-command-doesn-t-work-if-the-project-is-being-forked-to-another-storage' into 'master'

Allow gitlab-project's fork-project command to fork projects between different repository storages

Closes #51

See merge request !75

Unset GL_ID and GL_PROTOCOL immediately

Neither other code executing in the hook process nor subprocesses of
the hook process need access to the GL_ID / GL_PROTOCOL variables so
we can just unset them the moment we fetch them.

See merge request !73

Neither other code executing in the hook process nor subprocesses of
the hook process need access to the GL_ID / GL_PROTOCOL variables so
we can just unset them the moment we fetch them.

Add an error message when using shell commands with incompatible GitLab versions

Closes #48

See merge request !70

Allow GitLab Shell to check for allowed access based on the used Git protocol.

Needed for gitlab-org/gitlab-ce!4696 and gitlab-org/gitlab-ce#18601

See merge request !62

Remove hound config

Since we moved to gitlab.com we don't use Hound CI anymore. Instead we have rubocop.

See merge request !69

Use STDERR to output error messages

It's pretty minor change so I don't think we need a changelog item for this. 

Fixes https://gitlab.com/gitlab-org/gitlab-shell/issues/47

See merge request !68

Implement shard paths handling

See https://gitlab.com/gitlab-org/gitlab-ee/issues/583

See merge request !61

Prevent blocking custom hook output streams

Based on https://gitlab.com/gitlab-org/gitlab-shell/merge_requests/49

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/1458

See merge request !67