Documentation update for Ubuntu 18.04 LTS

docs/install.rst

@@ -26,6 +26,8 @@ Begin by installing the required applications and dependencies:
 
    sudo apt-get install python-dev build-essential mysql-server mysql-client graphviz docbook dblatex python-pip python-numpy git libmysqlclient-dev --no-install-recommends texlive-latex-extra docbook-utils inkscape libxml2-dev libxslt1-dev poppler-utils python-setuptools
 
+If you are installing Ubuntu 18.04 LTS or later, or have not been prompted to set a root database password, you will need to set this manually.  You can find instructions on how to do that `here <https://linuxconfig.org/how-to-reset-root-mysql-password-on-ubuntu-18-04-bionic-beaver-linux>`_.
+
 Clone the latest version of the CAIRIS github repository, and use pip to install the dependencies in the root directory, i.e.
 
 .. code-block:: bash