title: server certificate verification failed while running ansible playbook to checkout code from gituhub
body: <p>I am new to ansible. When I am using a playbook to check out code from github, I got the below error, i have <code>validate_certs=false</code> in my <code>ansible.cfg</code>.</p>
  
  <pre><code>ansible version 2.4.2
  platform : ubuntu xenial.
  
  fatal: [127.0.01]: FAILED! =&gt; {"changed": false, "cmd": "/usr/bin/git clone --origin origin https://github.com/cchurch/ansible-sign.git /root/src/ansible-sign", "msg": "Cloning into '/root/src/ansible-sign'...\nfatal: unable to access 'https://github.com/cchurch/ansible-sign.git/': server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none", "rc": 128, "stderr": "Cloning into '/root/src/ansible-sign'...\nfatal: unable to access 'https://github.com/cchurch/ansible-sign.git/': server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none\n", "stderr_lines": ["Cloning into '/root/src/ansible-sign'...", "fatal: unable to access 'https://github.com/cchurch/ansible-sign.git/': server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none"], "stdout": "", "stdout_lines": []}
  ===========================================================================
  </code></pre>
  
  <p><code>ansible-playbook</code>:</p>
  
  <pre><code>- hosts: all
    connection : local
    become: yes
    become_user : root
    become_method : sudo
    roles:
      - role: cchurch.scm
        scm_type: git
        scm_url: https://github.com/cchurch/ansible-sign.git
        scm_target_path: ~/src/hello-world
        scm_version: master
        scm_notify_on_updated: ansible sign updated
    handlers:
      - name: ansible sign updated
        debug:
          msg: "{{scm_target_path}} was updated from {{scm_url}} to {{scm_update_result.after}}."
  </code></pre>