title: error when adding a repository to install programs on ubuntu
body: <p>I am trying to install the Atom to be able to develop my sites, but this is having some conflict at the moment that I try to add the repository. The following output is displayed:</p>
  
  <pre><code>    marcius@Marcius-PC:~$ sudo add-apt-repository ppa:webupd8team/atom
  Traceback (most recent call last):
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 335, in get_ppa_info
      ret = get_ppa_info_from_lp(user, ppa)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 92, in get_ppa_info_from_lp
      return get_info_from_lp(lp_url)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 88, in get_info_from_lp
      return _get_https_content_py3(lp_url)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 110, in _get_https_content_py3
      lp_page = urllib.request.urlopen(request, cafile=LAUNCHPAD_PPA_CERT)
    File "/usr/lib/python3.5/urllib/request.py", line 153, in urlopen
      capath=capath)
    File "/usr/lib/python3.5/ssl.py", line 470, in create_default_context
      context.load_verify_locations(cafile, capath, cadata)
  ssl.SSLError: unknown error (_ssl.c:3053)
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File "/usr/bin/add-apt-repository", line 122, in &lt;module&gt;
      shortcut = shortcut_handler(line)
    File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 864, in shortcut_handler
      ret = factory(shortcut)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 407, in shortcut_handler
      return PPAShortcutHandler(shortcut)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 364, in __init__
      info = get_ppa_info(self.shortcut)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 347, in get_ppa_info
      _get_suggested_ppa_message(user, ppa))
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 304, in _get_suggested_ppa_message
      lp_user = get_info_from_lp(LAUNCHPAD_USER_API % user)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 88, in get_info_from_lp
      return _get_https_content_py3(lp_url)
    File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 110, in _get_https_content_py3
      lp_page = urllib.request.urlopen(request, cafile=LAUNCHPAD_PPA_CERT)
    File "/usr/lib/python3.5/urllib/request.py", line 153, in urlopen
      capath=capath)
    File "/usr/lib/python3.5/ssl.py", line 470, in create_default_context
      context.load_verify_locations(cafile, capath, cadata)
  ssl.SSLError: unknown error (_ssl.c:3053)
  marcius@Marcius-PC:~$ 
  </code></pre>
  
  <p>It seems to me that some problem with the dependencies of python, someone knows exactly what it is, and better how to correct?</p>