allow tagging and deployment of tagged app images

tests/unit/tag.bats

@@ -0,0 +1,47 @@
+#!/usr/bin/env bats
+
+load test_helper
+
+setup() {
+  deploy_app
+}
+
+teardown() {
+  destroy_app
+}
+
+@test "(tag) tag:add, tag:list, tag:rm" {
+  run /bin/bash -c "dokku tag:add $TEST_APP v0.9.0"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run /bin/bash -c "dokku tag:list $TEST_APP | egrep -q 'v0.9.0'"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+
+  run /bin/bash -c "dokku tag:rm $TEST_APP v0.9.0"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run /bin/bash -c "dokku tag:list $TEST_APP | egrep -q 'v0.9.0'"
+  echo "output: "$output
+  echo "status: "$status
+  assert_failure
+
+}
+
+@test "(tag) tag:deploy" {
+  run /bin/bash -c "dokku tag:add $TEST_APP v0.9.0"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run /bin/bash -c "dokku tag:deploy $TEST_APP v0.9.0"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+  run /bin/bash -c "docker ps | egrep '/start web'| egrep -q dokku/node-js-app:v0.9.0"
+  echo "output: "$output
+  echo "status: "$status
+  assert_success
+}