tests/docker: Install texinfo in the Fedora image

The 'makeinfo' is required to generate the documentation from
the 'html' Makefile rule (called by 'install-doc').
The NSIS installer uses these files.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190715174817.18981-6-philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

tests/docker/dockerfiles/fedora.docker

@@ -87,6 +87,7 @@ ENV PACKAGES \
     systemd-devel \
     systemtap-sdt-devel \
     tar \
+    texinfo \
     usbredir-devel \
     virglrenderer-devel \
     vte291-devel \