chore: add describe info for python2 (#17)

Author: stasadev

docker-compose.python2.yaml

@@ -5,3 +5,5 @@ services:
     image: python:2.7-slim-${DDEV_SITENAME}-built
     profiles:
       - python2
+    x-ddev:
+      describe-info: "For docker pull"

tests/test.bats

@@ -73,6 +73,10 @@ health_checks() {
   assert_success
   assert_output "('SSL:', 'OpenSSL 1.1.1d  10 Sep 2019')"
 
+  run ddev describe
+  assert_success
+  assert_output --partial "For docker pull"
+
   if [ "${USE_CUSTOM_NODE:-}" = "true" ]; then
     run ddev exec node -v
     assert_success