[FIX] Odoo 11.0: Add num2words installation

A Debian package does not exists yet for python3-num2words and
this package is required for those who want to render textual amounts.

Closes #129

11.0/Dockerfile

@@ -41,6 +41,7 @@ RUN set -x; \
         && rm -rf /var/lib/apt/lists/* odoo.deb
 
 # Copy entrypoint script and Odoo configuration file
+RUN pip3 install num2words
 COPY ./entrypoint.sh /
 COPY ./odoo.conf /etc/odoo/
 RUN chown odoo /etc/odoo/odoo.conf