chore: update babel dependencies (dequelabs#1443)

Author: jeeyyy

.babelrc

@@ -1,8 +1,15 @@
 {
   "presets": [
-    "env"
+    [
+      "@babel/preset-env"
+    ]
   ],
   "plugins": [
-    "transform-object-rest-spread"
+    [
+      "@babel/plugin-proposal-object-rest-spread",
+      {
+        "loose": true
+      }
+    ]
   ]
-}
+}

Gruntfile.js

@@ -73,7 +73,7 @@ module.exports = function(grunt) {
 		clean: ['dist', 'tmp', 'axe.js', 'axe.*.js'],
 		babel: {
 			options: {
-				compact: 'false'
+				compact: false
 			},
 			core: {
 				files: [

package.json

@@ -73,13 +73,12 @@
 		"fmt": "prettier --write *.{json,md,js} **/*.ts './{build,doc,lib,test}/**/*.{json,md,js,ts}'"
 	},
 	"devDependencies": {
-		"@babel/core": "^7.2.2",
+		"@babel/core": "^7.3.4",
+		"@babel/plugin-proposal-object-rest-spread": "^7.3.4",
+		"@babel/polyfill": "^7.2.5",
+		"@babel/preset-env": "^7.3.4",
 		"aria-query": "^3.0.0",
 		"axios": "^0.18.0",
-		"babel-core": "^6.26.0",
-		"babel-plugin-transform-object-rest-spread": "^6.6.5",
-		"babel-polyfill": "^6.7.4",
-		"babel-preset-env": "^1.7.0",
 		"babelify": "^10.0.0",
 		"blanket": "~1.2.3",
 		"browserify": "^16.2.3",
@@ -96,7 +95,7 @@
 		"fs-extra": "^7.0.0",
 		"globby": "^8.0.1",
 		"grunt": "^1.0.3",
-		"grunt-babel": "^7.0.0",
+		"grunt-babel": "^8.0.0",
 		"grunt-contrib-clean": "^2.0.0",
 		"grunt-contrib-concat": "^1.0.1",
 		"grunt-contrib-connect": "^2.0.0",