title: Call python-nmap PortScanner(), nmap not found
body: <p>In my virtualenv I installed python-nmap and nmap is installed (OS X).
  But if I call mmap like (virtualenv activated...):</p>
  
  <pre><code>import sys
  sys.path.append('/usr/local/bin')
  
  import nmap
  nm = nmap.PortScanner()
  </code></pre>
  
  <p>I get the following error:</p>
  
  <blockquote>
    <p>Raise PortScannerError('nmap program was not found in path')</p>
    
    <p>nmap.nmap.PortScannerError: 'nmap program was not found in path'</p>
  </blockquote>
  
  <p>Is there still another way to enter the path to nmap? </p>