title: Unable to open shp file
body: <p>So, I've been following Mike Bostock's tutorial on creating a map.</p>
  
  <p>To create the <code>subunits.json</code> GeoJSON file using <code>ogr2ogr</code> and <code>ne_10m_admin_0_map_subunits.shp</code> (which is the input) I typed:</p>
  
  <pre><code>ogr2ogr \
    -f GeoJSON \
    -where "ADM0_A3 IN ('GBR', 'IRL')" \
    subunits.json \
    ne_10m_admin_0_map_subunits.shp
  </code></pre>
  
  <p>but then I get:</p>
  
  <p><code>Unable to open datasource 'ne_10m_admin_0_map_subunits.shp' with the following drivers.</code></p>
  
  <p>I have qgis on my laptop and I though qgis would do the jack, but I guess not :P
  Does anyone have an idea how to fix it??</p>