[npm] added "clean" script

"npm run clean" will now find all excess files, confirm they should be deleted, and then delete them. To exclude a file pass it as the --ignore argument

package.json

@@ -56,7 +56,8 @@
     "lint": "grunt eslint:source",
     "lintroller": "grunt eslint:fixSource",
     "mocha": "mocha --compilers js:babel/register",
-    "mocha:debug": "mocha --debug-brk --compilers js:babel/register"
+    "mocha:debug": "mocha --debug-brk --compilers js:babel/register",
+    "clean": "grunt scrub"
   },
   "repository": {
     "type": "git",

tasks/scrub.js

@@ -0,0 +1,39 @@
+import { bgRed, white } from 'ansicolors';
+import { execSync } from 'child_process';
+import { createInterface } from 'readline';
+
+export default function (grunt) {
+
+  grunt.registerTask('scrub', function () {
+
+    const cmd = 'git clean -fdx';
+    const ignores = [
+      '.aws-config.json',
+      'config/kibana.dev.yml'
+    ]
+    .concat(String(grunt.option('ignore') || '').split(','))
+    .map(f => `-e "${f.split('"').join('\\"')}"`)
+    .reduce((all, arg) => `${all} ${arg}`, '');
+
+    const stdio = 'inherit';
+    execSync(`${cmd} -n ${ignores}`, { stdio });
+
+    const rl = createInterface({
+      input: process.stdin,
+      output: process.stdout
+    });
+    const danger = bgRed(white('DANGER'));
+
+    rl.on('close', this.async());
+    rl.question(`\n${danger} Do you really want to delete all of the above files?, [N/y] `, function (resp) {
+      var yes = resp.toLowerCase().trim()[0] === 'y';
+      rl.close();
+
+      if (yes) {
+        execSync(`${cmd} ${ignores}`, { stdio });
+      }
+    });
+
+  });
+
+}