Fix dead docs link

[ci skip]

doc/development/ci_setup.md

@@ -7,7 +7,7 @@ We currently use four CI services to test GitLab:
 1. GitLab CI on [GitHost.io](https://gitlab-ce.githost.io/projects/4/) for the [GitLab.com repo](https://gitlab.com/gitlab-org/gitlab-ce)
 2. GitLab CI at ci.gitlab.org to test the private GitLab B.V. repo at dev.gitlab.org
 3. [Semephore](https://semaphoreapp.com/gitlabhq/gitlabhq/) for [GitHub.com repo](https://github.com/gitlabhq/gitlabhq)
-4. [Mock CI Service](user/project/integrations/mock_ci.md) for local development
+4. [Mock CI Service](../user/project/integrations/mock_ci.md) for local development
 
 | Software @ configuration being tested | GitLab CI (ci.gitlab.org) | GitLab CI (GitHost.io) | Semaphore |
 |---------------------------------------|---------------------------|---------------------------------------------------------------------------|-----------|