README: remove Ubuntu 17.10 "Artful"

Packages are no longer built for Ubuntu 17.10 since
commit eb635bd, so
remove it from the README as well

Signed-off-by: Sebastiaan van Stijn <[email protected]>

Author: thaJeztah

README.md

@@ -8,7 +8,6 @@ This repository is solely maintained by Docker, Inc.
 The scripts will build for this list of packages types:
 
 * DEB packages for Ubuntu 18.04 Bionic
-* DEB packages for Ubuntu 17.10 Artful
 * DEB packages for Ubuntu 16.04 Xenial
 * DEB packages for Debian 10 Buster
 * DEB packages for Debian 9 Stretch