fix(create-twilio-function): handle rimraf failing (#400)

Received a report that creating a new project had failed for a developer
and then the cleanup task didn't end. There was an issue with deleting
the files that had been created which threw an unhandled error in the
cleanUpAndExit function leading to the spinner never stopping.

This adds a try/catch/finally around rimraf in cleanUpAndExit to ensure
that it does indeed exit.

packages/create-twilio-function/src/create-twilio-function.js

@@ -31,9 +31,16 @@ const successMessage = require('./create-twilio-function/success-message');
 async function cleanUpAndExit(projectDir, spinner, errorMessage) {
   spinner.fail(errorMessage);
   spinner.start('Cleaning up project directories and files');
-  await rimraf(projectDir);
-  spinner.stop().clear();
-  process.exitCode = 1;
+  try {
+    await rimraf(projectDir);
+  } catch (error) {
+    spinner.fail(
+      `There was an error cleaning up the project. Some files may still be present in ${projectDir}`
+    );
+  } finally {
+    spinner.stop().clear();
+    process.exitCode = 1;
+  }
 }
 
 async function performTaskWithSpinner(spinner, message, task) {