title: Can't start Rails
body: <p>I updated Rails and Ruby:</p>
  
  <pre><code>$ ruby -v
  ruby 2.1.5p273 (2014-11-13 revision 48405) [x86_64-darwin14.0]
  $ rails -v
  Rails 4.1.8
  </code></pre>
  
  <p>Now when I execute <code>rails server</code> I get this:</p>
  
  <pre><code>$ rails server
  Usage:
    rails new APP_PATH [options]
  
  Options:
    -r, [--ruby=PATH]                                   # Path to the Ruby binary of your choice
                                                        # Default: /Users/guilherme/.rbenv/versions/2.1.5/bin/ruby
    -m, [--template=TEMPLATE]                           # Path to some application template (can be a filesystem path or URL)
    [--skip-gemfile], [--no-skip-gemfile]               # Don't create a Gemfile
    -B, [--skip-bundle], [--no-skip-bundle]             # Don't run bundle install
    { ... }
  </code></pre>
  
  <p>What I have to do to start Rails?</p>