Doesn't work with PDF. Tried this:

```rst
.. image:: /_images/ceph_nodes.svg
  :width: 100%
  :align: center
```

Got back:

writing Fuel-for-OpenStack-3.2-ReferenceArchitecture... [ERROR] image.py:357 The image (/home/angdraug/work/mirantis/git/fuel-docs/_images/ceph_nodes.svg, near line UNKNOWN in file UNKNOWN) is broken or in an unknown format.