Merge pull request #17 from DNNX/master

Add :slack_application_url support

README.markdown

@@ -27,6 +27,8 @@ set :slack_subdomain, "kohactive" # if your subdomain is kohactive.slack.com
 set :slack_application, "Rocketman"
 set :slack_username, "Elton John"
 set :slack_emoji, ":rocket:"
+set :slack_application_url, "http://my-awesome-app.example.com"
+# set(:slack_application_url) { "http://{ fetch :domain_aliases }" }
 ```
 
 You can obtain your `webhook_token` from the integrations section of the team page in Slack.  

lib/capistrano/slack.rb

@@ -32,9 +32,10 @@ def self.extended(configuration)
               slack_username = fetch(:slack_username) || "deploybot"
               slack_application = fetch(:slack_application) || application
               slack_subdomain = fetch(:slack_subdomain)
+              slack_application_url = fetch(:slack_application_url, nil)
               return if slack_token.nil?
               announced_deployer = ActiveSupport::Multibyte::Chars.new(fetch(:deployer)).mb_chars.normalize(:kd).gsub(/[^\x00-\x7F]/,'').to_s
-              announced_stage = fetch(:stage, 'production')
+              announced_stage = slack_application_url || fetch(:stage, 'production')
 
               announcement = if fetch(:branch, nil)
                                "#{announced_deployer} is deploying #{slack_application}'s #{branch}"
@@ -70,9 +71,10 @@ def self.extended(configuration)
                 slack_username = fetch(:slack_username) || "deploybot"
                 slack_application = fetch(:slack_application) || application
                 slack_subdomain = fetch(:slack_subdomain)
+                slack_application_url = fetch(:slack_application_url, nil)
                 return if slack_token.nil?
                 announced_deployer = fetch(:deployer)
-                announced_stage = fetch(:stage, 'production')
+                announced_stage = slack_application_url || fetch(:stage, 'production')
                 end_time = Time.now
                 start_time = fetch(:start_time)
                 elapsed = end_time.to_i - start_time.to_i