Refactor action to typescript (#226)

* Refactor to typescript (config part)

* Refactor to typescript (convert extensions, minor fixes)

* Refactor to typescript (move from `action` to `dist`)

* Re-enable integrity-check for dist index.js

* Fix all tests and lints

* fix parsing major versions

* Test patch level to be digits only

* debug

* debug

* uncache

* manual compile

* debug

* debug

* Debug

* Build lib - doh

* remove diff check

* Make kubernetes workflow manual

* Properly generate 3 digit for simple major tags

* Remove ts-ignore

* re-enable cache

src/model/cache.ts

@@ -0,0 +1,26 @@
+import * as core from '@actions/core';
+import fs from 'fs';
+import Action from './action';
+import Project from './project';
+
+class Cache {
+  static verify() {
+    if (!fs.existsSync(Project.libraryFolder)) {
+      this.notifyAboutCachingPossibility();
+    }
+  }
+
+  static notifyAboutCachingPossibility() {
+    if (Action.isRunningLocally) {
+      return;
+    }
+
+    core.warning(`
+      Library folder does not exist.
+      Consider setting up caching to speed up your workflow,
+      if this is not your first build.
+    `);
+  }
+}
+
+export default Cache;