Merge pull request #8 from crushlovely/master

Added npm:prune task.

lib/capistrano/tasks/npm.rake

@@ -19,11 +19,35 @@ namespace :npm do
   end
 
   before 'deploy:updated', 'npm:install'
+
+  desc <<-DESC
+        Remove extraneous packages via npm. This command is executed within \
+        the same context as npm install using the npm_roles and npm_target_path \
+        variables.
+
+        By default prune will be executed with the --production flag.  You can \
+        override this default by setting the variable shown below.
+
+          set :npm_prune_flags, '--production'
+
+        This task is strictly opt-in.  If you want to run it on every deployment \
+        before you run npm install, add the following to your deploy.rb.
+
+          before 'npm:install', 'npm:prune'
+    DESC
+  task :prune do
+    on roles fetch(:npm_roles) do
+      within fetch(:npm_target_path, release_path) do
+        execute :npm, 'prune', fetch(:npm_prune_flags)
+      end
+    end
+  end
 end
 
 namespace :load do
   task :defaults do
     set :npm_flags, '--production --silent'
+    set :npm_prune_flags, '--production'
     set :npm_roles, :all
   end
 end