Merge pull request docker#10284 from thaJeztah/add_eoan_to_install

Install: add Ubuntu Eoan, and remove old non-LTS versions

Author: usha-mandya

install/linux/docker-ce/ubuntu.md

@@ -32,8 +32,7 @@ To learn more about Docker EE, see
 To install Docker Engine - Community, you need the 64-bit version of one of these Ubuntu
 versions:
 
-- Disco 19.04
-- Cosmic 18.10
+- Eoan 19.10
 - Bionic 18.04 (LTS)
 - Xenial 16.04 (LTS)