title: Including pybind11 cmake files with Hunter
body: <p>I am using Hunter to manage dependencies of my project.
  One of them is <code>pybind11</code>
  It has been installed correctly and I can use it in my code.
  However when building my project with CMake I need to use some cmake function provided by <code>pybind11</code> in some cmake files.
  These are located in <code>pybind11_DIR</code>
  How can I include them ?</p>
  
  <p>Before I was used to only do that <code>add_subdirectory(pybind11)</code> to have everything included.</p>
  
  <p>Thanks</p>