update download page to say ubuntu 18 for 1.17.0
diff --git a/download.html b/download.html
index 76af104..0d89739 100644
--- a/download.html
+++ b/download.html
@@ -72,7 +72,7 @@
 
 						<li><a onclick="_gaq.push(['_trackEvent', 'Outbound Links', 'Click', 'madlib-1.17.0-bin-Linux.rpm']);"  href="https://dist.apache.org/repos/dist/release/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.rpm">Linux</a>           (<a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.rpm.asc">pgp</a>,  <a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.rpm.sha512">sha512</a>) — CentOS / Red Hat 6 and higher (64 bit). GPDB 5.x, GPDB 6.x, PostgreSQL 11.x and 12.x.</li>
 
-						<li><a onclick="_gaq.push(['_trackEvent', 'Outbound Links', 'Click', 'madlib-1.17.0-bin-Linux.deb']);"  href="https://dist.apache.org/repos/dist/release/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.deb">Linux</a>           (<a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.deb.asc">pgp</a>,  <a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.deb.sha512">sha512</a>) — Ubuntu 16.04. GPDB 5.x, GPDB 6.x, PostgreSQL 11.x and 12.x.</li>
+						<li><a onclick="_gaq.push(['_trackEvent', 'Outbound Links', 'Click', 'madlib-1.17.0-bin-Linux.deb']);"  href="https://dist.apache.org/repos/dist/release/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.deb">Linux</a>           (<a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.deb.asc">pgp</a>,  <a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Linux.deb.sha512">sha512</a>) — Ubuntu 18.04. GPDB 5.x, GPDB 6.x, PostgreSQL 11.x and 12.x.</li>
 
 						<li><a onclick="_gaq.push(['_trackEvent', 'Outbound Links', 'Click', 'madlib-1.17.0-bin-Darwin.dmg']);" href="https://dist.apache.org/repos/dist/release/madlib/1.17.0/apache-madlib-1.17.0-bin-Darwin.dmg">Mac OS X</a>       (<a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Darwin.dmg.asc">pgp</a>, <a href="https://www.apache.org/dist/madlib/1.17.0/apache-madlib-1.17.0-bin-Darwin.dmg.sha512">sha512</a>) — OS 10.6 and higher.  PostgreSQL 11.x and 12.x.</li>
 					</ul>