add sample project in ruby on rails with postgres

Signed-off-by: Lukas Pol <lukaspaespol@gmail.com>

ruby_on_rails-postgres/bin/rake

@@ -0,0 +1,9 @@
+#!/usr/bin/env ruby
+begin
+  load File.expand_path('../spring', __FILE__)
+rescue LoadError => e
+  raise unless e.message.include?('spring')
+end
+require_relative '../config/boot'
+require 'rake'
+Rake.application.run