Bump version to 3.0.0

Gemfile.lock

 PATH
   remote: .
   specs:
-    gitlab-monitor (2.19.1)
+    gitlab-monitor (3.0.0)
       connection_pool (~> 2.2.1)
       pg (~> 0.18.4)
       quantile (~> 0.2.0)
@@ -20,7 +20,7 @@ GEM
     pg (0.18.4)
     powerpack (0.1.1)
     quantile (0.2.1)
-    rack (1.6.10)
+    rack (1.6.11)
     rack-protection (1.5.5)
       rack
     rainbow (2.1.0)
@@ -47,7 +47,7 @@ GEM
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
     ruby-progressbar (1.8.1)
-    sidekiq (5.2.1)
+    sidekiq (5.2.3)
       connection_pool (~> 2.2, >= 2.2.2)
       rack-protection (>= 1.5.0)
       redis (>= 3.3.5, < 5)

lib/gitlab_monitor/version.rb

 module GitLab
   module Monitor
-    VERSION = "2.19.1".freeze
+    VERSION = "3.0.0".freeze
   end
 end