title: Issue: “OSError: /usr/lib/libyara.so: cannot open shared object file: No such file or directory” while running cuckoo.py
body: <p>I have installed cuckoo and all the dependencies and have also created VM using virtual box.
  I am getting an error <code>"OSError: /usr/lib/libyara.so: cannot open shared object file: No such file or directory"</code> whenever i try to run cuckoo.py using python</p>
  
  <p>I have tried searching in all forums and also tested whether yara is installed properly. It seems to be working fine using terminal. Checked that libyara.so is present in /usr/local/lib and python or cuckoo is checking in /usr/lib/</p>
  
  <p>Also tried updating local library using</p>
  
  <p><code>sudo echo "/usr/local/lib" >> /etc/ld.so.conf
  sudo ldconfig </code></p>
  
  <p>I have installed yara using tar ball. Have also used --enable-cuckoo --enable-magic args too.</p>
  
  <p>Where might have I gone wrong?</p>
  
  <p>Configuration of my system: 
  Ubuntu 16.04;
  python 2.7;
  yara 3.4.0</p>