Cleanup unit test

tests/unit/cleanup.bats

@@ -0,0 +1,35 @@
+#!/usr/bin/env bats
+
+load test_helper
+
+setup() {
+  deploy_app
+}
+
+teardown() {
+  destroy_app
+}
+
+@test "remove exited containers" {
+  run dokku run $TEST_APP hostname
+  echo "output: "$output
+  echo "status: "$status
+  container="$output"
+  assert_success
+  run bash -c "docker ps -a -f 'status=exited' -q --no-trunc=false | grep -q $container"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run dokku cleanup
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run bash -c "docker ps -a -f 'status=exited' -q --no-trunc=false | grep -q $container"
+  echo "output: "$output
+  echo "status: "$status
+  assert_failure
+  run bash -c "docker ps -a -f 'status=exited' -q --no-trunc=false"
+  echo "output: "$output
+  echo "status: "$status
+  assert_output ""
+}