chore: Add lockfile to integration-test project

integration-test/.eslintignore

@@ -0,0 +1,4 @@
+node_modules
+cdk.out
+.eslintrc.js
+jest.config.js

integration-test/.eslintrc.js

@@ -0,0 +1,20 @@
+module.exports = {
+  root: true,
+  env: {
+    node: true,
+    jest: true,
+  },
+  extends: ["@guardian/eslint-config-typescript"],
+  parserOptions: {
+    ecmaVersion: 2020,
+    tsconfigRootDir: __dirname,
+    sourceType: "module",
+    project: ["./tsconfig.eslint.json"],
+  },
+  plugins: ["@typescript-eslint"],
+  rules: {
+    "@typescript-eslint/no-inferrable-types": 0,
+    "import/no-namespace": 2,
+  },
+  ignorePatterns: ["**/*.js", "node_modules"],
+};

integration-test/.gitignore

@@ -1,7 +1,2 @@
 # Output directory for generated cloudformation.
 cdk.out
-
-# Ignore package-lock.json to avoid the following error when reinstalling dependencies:
-#   npm ERR! notarget No matching version found for eslint-plugin-custom-rules@1.0.0.
-# This is because we're installing @guardian/cdk from file, which is in turn installing eslint-plugin-custom-rules from file.
-package-lock.json

integration-test/.prettierrc

@@ -0,0 +1,3 @@
+{
+  "printWidth": 120
+}

integration-test/README.md

@@ -9,14 +9,3 @@ The purpose of this is to ensure:
 This is in reaction to [#356](https://github.com/guardian/cdk/pull/356) and [#365](https://github.com/guardian/cdk/pull/365) which broke the package.
 The integration test helps increase confidence in any future changes to the library, _before_ publishing them.
 That is, the feedback loop is shortened.
-
-## A note about linting
-As we're not using a lockfile, our dependency versions are non-deterministic.
-
-This means we can install versions of eslint plugins with updated rules that cause the project to fail the lint check.
-
-Rather than [firefight](https://github.com/guardian/cdk/pull/564) this, we're simply not linting this project as:
-  - This project is never consumed by anyone
-  - This project doesn't run anywhere
-  - This project doesn't get updated too often
-  - Understanding the original lockfile issues is a time sink