title: dlib not using CUDA
body: <p>I installed dlib using pip. my graphic card supports CUDA, but while running dlib, it is not using GPU. </p>
  
  <p>Im working on ubuntu 18.04</p>
  
  <pre><code>Python 3.6.5 (default, Apr  1 2018, 05:46:30) 
  [GCC 7.3.0] on linux
  &gt;&gt;&gt; import dlib
  &gt;&gt;&gt; dlib.DLIB_USE_CUDA
  False
  </code></pre>
  
  <p>I have also installed the NVidia Cuda Compile driver but still it is not working.</p>
  
  <pre><code>nvcc --version
  nvcc: NVIDIA (R) Cuda compiler driver
  Copyright (c) 2005-2017 NVIDIA Corporation
  Built on Fri_Nov__3_21:07:56_CDT_2017
  Cuda compilation tools, release 9.1, V9.1.85
  </code></pre>
  
  <p>Can anyone help me how to get it working. ?</p>