Remove Ubuntu Artful test (#127)

* Remove Ubuntu artful test

* Remove Artful from Travis build matrix

.travis.yml

@@ -168,34 +168,6 @@ matrix:
         distribution: ubuntu
         version: xenial
         playbook: unit
-    - env:
-        distribution: ubuntu
-        version: artful
-        playbook: basic
-    - env:
-        distribution: ubuntu
-        version: artful
-        playbook: http-template
-    - env:
-        distribution: ubuntu
-        version: artful
-        playbook: modules
-    - env:
-        distribution: ubuntu
-        version: artful
-        playbook: push
-    - env:
-        distribution: ubuntu
-        version: artful
-        playbook: stable
-    - env:
-        distribution: ubuntu
-        version: artful
-        playbook: stream-template
-    - env:
-        distribution: ubuntu
-        version: artful
-        playbook: unit
     - env:
         distribution: ubuntu
         version: bionic

tests/dockerfiles/Dockerfile.ubuntu-artful

@@ -1,15 +0,0 @@
-FROM ubuntu:artful
-
-RUN apt-get update && apt-get dist-upgrade -y && apt-get install -y software-properties-common && rm -rf /var/lib/apt/lists/*
-
-RUN apt-add-repository -y ppa:ansible/ansible && apt-get update && apt-get install -y \
-    git \
-    ansible \
-    apt-transport-https \
-    curl \
-    init \
- && rm -rf /var/lib/apt/lists/*
-
-RUN echo "[local]\nlocalhost ansible_connection=local" > /etc/ansible/hosts
-
-ENTRYPOINT ["/sbin/init"]