updated docker-compose to fetch latest version without specifying which one

roles/docker/tasks/ubuntu.yml

@@ -28,7 +28,8 @@
 #install compose:
 
 - name: download compose
-  shell: curl -L https://github.com/docker/compose/releases/download/{{ compose_ver }}/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose
+#  shell: curl -L https://github.com/docker/compose/releases/download/{{ compose_ver }}/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose
+  shell: curl -s https://api.github.com/repos/docker/compose/releases/latest | grep browser_download_url | grep docker-compose-linux-x86_64 | grep -v sha256 | cut -d '"' -f 4 | wget -O /usr/local/bin/docker-compose -qi -
 
-- name: link compose
+- name: make compose executable
   shell: chmod +x /usr/local/bin/docker-compose