Bump grunt from 0.4.5 to 1.5.2

Bumps [grunt](https://github.com/gruntjs/grunt) from 0.4.5 to 1.5.2.
- [Release notes](https://github.com/gruntjs/grunt/releases)
- [Changelog](https://github.com/gruntjs/grunt/blob/main/CHANGELOG)
- [Commits](https://github.com/gruntjs/grunt/compare/v0.4.5...v1.5.2)

---
updated-dependencies:
- dependency-name: grunt
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -20,7 +20,7 @@
   "devDependencies": {
     "browserify": "^9.0.8",
     "chai": "^2.2.0",
-    "grunt": "^0.4.5",
+    "grunt": "^1.5.2",
     "grunt-babel": "^5.0.0",
     "grunt-browserify": "^3.7.0",
     "grunt-contrib-uglify": "^0.9.1",