Added check_redis_version to check.rake

王权利请求将github/fork/axilleas/check-redis合并到master

Created by: axilleas

Since many people install GitLab on old versions of Debian/Ubuntu, an old version (<2.0.0) of redis is installed as well. To avoid confusion and repeated posts in the forum, I added a function to check redis version.

合并请求报告