Add build docker image to CI (#7332)

* add build docker image to CI

* remove node setup

* removed local dependency to test passing docker build

* Update CHANGELOG.md

* Revert "removed local dependency to test passing docker build"

This reverts commit a7801e1874be206c9f3f7bfd367766546bf483b6.

* removed unnecessary docker build options

* fixed docker build

spec/dependencies/mock-mail-adapter/index.js

@@ -0,0 +1,15 @@
+/**
+ * A mock mail adapter for testing.
+ */
+class MockMailAdapter {
+  constructor(options = {}) {
+    if (options.throw) {
+      throw 'MockMailAdapterConstructor';
+    }
+  }
+  sendMail() {
+    return 'MockMailAdapterSendMail';
+  }
+}
+
+module.exports = MockMailAdapter;

spec/dependencies/mock-mail-adapter/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "mock-mail-adapter",
+  "version": "1.0.0",
+  "description": "Mock mail adapter for tests.",
+  "main": "index.js"
+}