Update ansible-test default test containers.

changelogs/fragments/ansible-test-default-3.1.0.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - ansible-test - Updated the default test containers to version 3.1.0.

test/lib/ansible_test/_data/completion/docker.txt

@@ -1,5 +1,5 @@
-default name=quay.io/ansible/default-test-container:3.0.0 python=3.6,2.6,2.7,3.5,3.7,3.8,3.9 seccomp=unconfined context=collection
+default name=quay.io/ansible/default-test-container:3.1.0 python=3.6,2.6,2.7,3.5,3.7,3.8,3.9 seccomp=unconfined context=collection
-default name=quay.io/ansible/ansible-core-test-container:3.0.0 python=3.6,2.6,2.7,3.5,3.7,3.8,3.9 seccomp=unconfined context=ansible-core
+default name=quay.io/ansible/ansible-core-test-container:3.1.0 python=3.6,2.6,2.7,3.5,3.7,3.8,3.9 seccomp=unconfined context=ansible-core
 alpine3 name=quay.io/ansible/alpine3-test-container:2.0.1 python=3.8
 centos6 name=quay.io/ansible/centos6-test-container:2.0.1 python=2.6 seccomp=unconfined
 centos7 name=quay.io/ansible/centos7-test-container:2.0.1 python=2.7 seccomp=unconfined