[stable-2.5] Reduce testing of Ubuntu versions.

Removing:

- Ubuntu 14.04 with Python 2.7
- Ubuntu 16.04 with Python 3.5

Keeping:

- Ubuntu 16.04 with Python 2.7
- Ubuntu 18.04 with Python 3.6.
(cherry picked from commit c8f2becb7a)

Co-authored-by: Matt Clay <matt@mystile.com>

shippable.yml

@@ -53,9 +53,7 @@ matrix:
     - env: T=linux/fedora28/1
     - env: T=linux/fedora29/1
     - env: T=linux/opensuse42.3/1
-    - env: T=linux/ubuntu1404/1
     - env: T=linux/ubuntu1604/1
-    - env: T=linux/ubuntu1604py3/1
     - env: T=linux/ubuntu1804/1
 
     - env: T=osx/10.11/2
@@ -66,9 +64,7 @@ matrix:
     - env: T=linux/fedora28/2
     - env: T=linux/fedora29/2
     - env: T=linux/opensuse42.3/2
-    - env: T=linux/ubuntu1404/2
     - env: T=linux/ubuntu1604/2
-    - env: T=linux/ubuntu1604py3/2
     - env: T=linux/ubuntu1804/2
 
     - env: T=osx/10.11/3
@@ -79,9 +75,7 @@ matrix:
     - env: T=linux/fedora28/3
     - env: T=linux/fedora29/3
     - env: T=linux/opensuse42.3/3
-    - env: T=linux/ubuntu1404/3
     - env: T=linux/ubuntu1604/3
-    - env: T=linux/ubuntu1604py3/3
     - env: T=linux/ubuntu1804/3
 
     - env: T=aws/2.7/1

test/runner/completion/docker.txt

@@ -4,7 +4,5 @@ centos7 name=quay.io/ansible/centos7-test-container:1.4.0 seccomp=unconfined
 fedora28 name=quay.io/ansible/fedora28-test-container:1.5.0
 fedora29 name=quay.io/ansible/fedora29-test-container:1.5.0 python=3
 opensuse42.3 name=quay.io/ansible/opensuse42.3-test-container:1.4.0 seccomp=unconfined
-ubuntu1404 name=quay.io/ansible/ubuntu1404-test-container:1.4.0 seccomp=unconfined
 ubuntu1604 name=quay.io/ansible/ubuntu1604-test-container:1.4.0 seccomp=unconfined
-ubuntu1604py3 name=quay.io/ansible/ubuntu1604py3-test-container:1.4.0 seccomp=unconfined python=3
 ubuntu1804 name=quay.io/ansible/ubuntu1804-test-container:1.6.0 seccomp=unconfined python=3