Revert "Add yarn install task to mina"

This reverts commit d6000ca56c.

config/deploy.rb

@@ -123,16 +123,6 @@ task :setup => :environment do
   queue %[echo "-----> Be sure to edit 'shared/environments/staging.rb'."]
 end
 
-namespace :yarn do
-  desc "Install package dependencies using yarn."
-  task :install do
-    queue %{
-      echo "-----> Installing package dependencies using yarn"
-      #{echo_cmd %[yarn install --non-interactive]}
-    }
-  end
-end
-
 desc "Deploys the current version to the server."
 task :deploy => :environment do
   queue 'export PATH=$PATH:/usr/local/rbenv/bin:/usr/local/rbenv/shims'
@@ -143,7 +133,7 @@ task :deploy => :environment do
     invoke :'git:clone'
     invoke :'deploy:link_shared_paths'
     invoke :'bundle:install'
-    invoke :'yarn:install'
+    command 'yarn install --non-interactive'
     invoke :'rails:db_migrate'
     invoke :'rails:assets_precompile:force'