refactored rake task and make build pass

.gitlab-ci.yml

@@ -183,7 +183,7 @@ spinach:ruby21:
 notify:slack:
   stage: notifications
   script:
-    - bundle exec rake ci:slack:error
+    - bundle exec rake ci:slack:error["#ci-test","Build failed for master/tags"]
   when: on_failure
 #  only:
 #    - master

app/models/project.rb

@@ -42,8 +42,7 @@
 require 'carrierwave/orm/activerecord'
 require 'file_size_validator'
 
-
-lass Project < ActiveRecord::Base
+class Project < ActiveRecord::Base
   include Gitlab::ConfigHelper
   include Gitlab::ShellAdapter
   include Gitlab::VisibilityLevel

lib/tasks/ci/slack.rake

 namespace :ci do
   namespace :slack do
     desc "GitLab CI | Send slack notification on build failure"
-    task error: :environment do
-      error_text = 'Build failed for master/tags'
-      Kernel.system "curl -X POST --data-urlencode 'payload={\"channel\": \"#ci-test\", \"username\": \"gitlab-ci\", \"text\": \"#{error_text}\", \"icon_emoji\": \":gitlab:\"}' $CI_SLACK_WEBHOOK_URL"
+    task :error, [:channel, :error] do |t, args|
+      next unless !"#{ENV['CI_SLACK_WEBHOOK_URL']}".blank? && args.channel && args.error
+      Kernel.system "curl -X POST --data-urlencode 'payload={\"channel\": \"#{args.channel}\", \"username\": \"gitlab-ci\", \"text\": \"#{args.error}\", \"icon_emoji\": \":gitlab:\"}' $CI_SLACK_WEBHOOK_URL"
     end
   end
 end