Bump version to 0.0.22

Gemfile.lock

 PATH
   remote: .
   specs:
-    gitlab-monitor (0.0.21)
+    gitlab-monitor (0.0.22)
       pg (~> 0.18.4)
       quantile (~> 0.2.0)
       redis-namespace (~> 1.5.2)

lib/gitlab_monitor/version.rb

 module GitLab
   module Monitor
-    VERSION = "0.0.21".freeze
+    VERSION = "0.0.22".freeze
   end
 end