Signed-off-by: David Greaves <david.greaves@jollamobile.com>

5.0-to-5.1.md - gitlab-shell update instructions.

Fix error "Address already in use".

Use secure Gravatar url when https is set to true in the configuration

Show CI status even for closed MR. Use green bg for "Merged by username" message and red for closed one

Fix: API 500 error when project does not exists

Fix overflow of text in the project summary box in Chrome and Safari

Merge pull request #3583 from karlhungus/update_dev_setup_to_not_use_hard_coded_path_to_gitlab_shell

Updated setup to reference the gitlab-shell var

Added os_name support for systems running systemd.

Added check_redis_version to check.rake

Fixed typo in gitlab.yml.example