title: Module whois not working in Python 3 even after importing it
body: <p>Please Check the following output i get after installing and import whois module
  can someone help with this issue ?</p>
  
  <pre><code>Python 3.6.7 (default, Oct 22 2018, 11:32:17) 
  [GCC 8.2.0] on linux
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import whois
  &gt;&gt;&gt; domain = whois.query('www.google.com')
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/usr/local/lib/python3.6/dist-packages/whois/__init__.py", line 50, in query
      pd = do_parse(do_query(d, force, cache_file, slow_down, ignore_returncode), tld)
    File "/usr/local/lib/python3.6/dist-packages/whois/_1_query.py", line 44, in do_query
      _do_whois_query(dl, ignore_returncode),
    File "/usr/local/lib/python3.6/dist-packages/whois/_1_query.py", line 58, in _do_whois_query
      p = subprocess.Popen(['whois', '.'.join(dl)], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    File "/usr/lib/python3.6/subprocess.py", line 709, in __init__
      restore_signals, start_new_session)
    File "/usr/lib/python3.6/subprocess.py", line 1344, in _execute_child
      raise child_exception_type(errno_num, err_msg, err_filename)
  FileNotFoundError: [Errno 2] No such file or directory: 'whois': 'whois'
  `
  </code></pre>