Move all samples to the root dir

Signed-off-by: Anca Iordache <anca.iordache@docker.com>

react-express-mysql/backend/healthcheck.js

@@ -0,0 +1,21 @@
+var http = require("http");
+
+var options = {
+  timeout: 2000,
+  host: 'localhost',
+  port: process.env.PORT || 8080,
+  path: '/healthz' // must be the same as HEALTHCHECK in Dockerfile
+};
+
+var request = http.request(options, (res) => {
+  console.info('STATUS: ' + res.statusCode);
+  process.exitCode = (res.statusCode === 200) ? 0 : 1;
+  process.exit();
+});
+
+request.on('error', function(err) {
+  console.error('ERROR', err);
+  process.exit(1);
+});
+
+request.end();