title: Elixir: Mix aliases, two `run` tasks in one alias
body: <p>When setting aliases like:</p>
  
  <pre><code>defp aliases do
      [
        test_run: ["run -e 'IO.puts(\"One\")'", "run -e 'IO.puts(\"Two\")'"]
      ]
  end
  </code></pre>
  
  <p>The result of <code>mix test_run</code> should be</p>
  
  <pre><code>$ mix test_run
  One
  Two
  </code></pre>
  
  <p>But it only executes the first task and prints </p>
  
  <pre><code>$ mix test_run
  One
  </code></pre>
  
  <p>Not sure if it's intended behaviour, but before putting an issue I wanted to make sure.
  Here is the repository to reproduce the error:
  <a href="https://github.com/wende/mix_run_twice" rel="nofollow">https://github.com/wende/mix_run_twice</a></p>