Update readme with deployment instructions and deployment script (#411)

* Update readme with deployment instructions and deployment script

* Update travis

Author: edwinthinks

.travis.yml

@@ -30,7 +30,7 @@ after_success:
     chmod 600 config/deploy_id_rsa;
     eval `ssh-agent -s`;
     ssh-add config/deploy_id_rsa;
-    bundle exec cap staging deploy;
+    BRANCH=master bundle exec cap staging deploy;
     ssh-agent -k;
     fi
 env:

README.md

@@ -96,3 +96,6 @@ Keep in mind that you need js to be enabled. For example:
 ```
 describe "PickupSheet", type: :feature, js: true do
 ```
+
+# Deployment Process
+Please follow the deployment instructions in the associated diaper application [here](https://github.com/rubyforgood/diaper#deployment-process)

config/deploy.rb

@@ -26,7 +26,15 @@
 
 ## Defaults:
 # set :scm,           :git
-set :branch, ENV["BRANCH"] || :master
+set :branch do
+  if ENV["TAG"] && ENV["BRANCH"]
+    raise "You can only specify either TAG or BRANCH"
+  elsif ENV["TAG"]
+    ENV["TAG"]
+  elsif ENV["BRANCH"]
+    ENV["BRANCH"]
+  end
+end
 # set :format,        :pretty
 # set :log_level,     :debug
 # set :keep_releases, 5
@@ -51,9 +59,8 @@
   desc "Make sure local git is in sync with remote."
   task :check_revision do
     on roles(:app) do
-      unless `git rev-parse HEAD` == `git rev-parse origin/master`
-        puts "WARNING: HEAD is not the same as origin/master"
-        puts "Run `git push` to sync changes."
+      if fetch(:branch).nil?
+        puts "You must provide either a TAG or a BRANCH. Example: 'TAG=2.2.0 cap <environment> deploy'"
         exit
       end
     end