docs/devel/testing: Fix typo in dockerfile path

Signed-off-by: NLiam Merwick <liam.merwick@oracle.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NLi Qiang <liq3ea@gmail.com>
Message-Id: <1561727317-30655-1-git-send-email-liam.merwick@oracle.com>
Signed-off-by: NLaurent Vivier <laurent@vivier.eu>

docs/devel/testing.rst

@@ -327,7 +327,7 @@ Images
 ------
 
 Along with many other images, the ``min-glib`` image is defined in a Dockerfile
-in ``tests/docker/dockefiles/``, called ``min-glib.docker``. ``make docker``
+in ``tests/docker/dockerfiles/``, called ``min-glib.docker``. ``make docker``
 command will list all the available images.
 
 To add a new image, simply create a new ``.docker`` file under the