Build: Revert grunt from 1.0.1 to 0.4.5

grunt-compare-size specifies grunt ">= 0.4.0 < 0.5" in its peerDependencies
which makes `npm install` break with npm <3.

Refs rwaldron/grunt-compare-size#25

Author: mgol

package.json

@@ -29,7 +29,7 @@
     "commitplease": "2.3.1",
     "core-js": "2.2.2",
     "cross-spawn": "2.2.3",
-    "grunt": "1.0.1",
+    "grunt": "0.4.5",
     "grunt-babel": "6.0.0",
     "grunt-cli": "1.2.0",
     "grunt-compare-size": "0.4.0",