fix(lib): corrupted manifests when including large files (#350)

The code in `_loadurl.js` which reads manifests from files did not wait until the entire input was written to stdout before it exited.

The fix is not to `exit(0)` but rather just let node exit gracefully.

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/cdk8s/src/_loadurl.js

@@ -22,24 +22,22 @@ if (!purl.protocol) {
     throw new Error(`unable to parse pathname from file url: ${url}`);
   }
 
-  process.stdout.write(fs.readFileSync(purl.pathname, 'utf-8'));
-  process.exit(0);
+  fs.createReadStream(purl.pathname).pipe(process.stdout);
+} else {
+  const client = getHttpClient();
+  const get = client.get(url, response => {
+    if (response.statusCode !== 200) {
+      throw new Error(`${response.statusCode} response from http get: ${response.statusMessage}`);
+    }
+
+    response.on('data', chunk => process.stdout.write(chunk));
+  });
+
+  get.once('error', err => {
+    throw new Error(`http error: ${err.message}`);
+  });
 }
 
-const client = getHttpClient();
-
-const get = client.get(url, response => {
-  if (response.statusCode !== 200) {
-    throw new Error(`${response.statusCode} response from http get: ${response.statusMessage}`);
-  }
-
-  response.on('data', chunk => process.stdout.write(chunk));
-});
-
-get.once('error', err => {
-  throw new Error(`http error: ${err.message}`);
-});
-
 function getHttpClient() {
   switch (purl.protocol) {
     case 'http:': return http;