title: Ansible become_user asks for password even though it is configured passwordless
body: <p>I have a strange issue which after many searches, I was not able to find an answer.
  It is a very simple case.</p>
  
  <p>Currently there is a linux machine with user x and user y. When I manually login to user x, I can switch user y passwordless using: "sudo su - y".</p>
  
  <p>Now back to ansible.</p>
  
  <pre><code>tasks:
  - name: test task
    shell: echo "this is a test"
    become: true
    become_user: y
  </code></pre>
  
  <p>This task will connect to the machine using user x. To run the echo it becomes y. For this situation I am getting:
      "module_stdout": "sudo: a password is required\r\n",</p>
  
  <p>for user y I provided a sudoers file with /bin/sh *, also does not work.
  Anyone have an idea?</p>
  
  <p>Thanks in advance.</p>