Update Grunt tasks

Author: Adrien Grsmto

package.json

@@ -10,13 +10,13 @@
 	"homepage": "https://grsmto.github.io/simplebar/",
 	"version": "1.1.2",
 	"devDependencies": {
-		"grunt": "~0.4.1",
-		"grunt-cli": "~0.1.7",
-		"grunt-contrib-jshint": "~0.4.3",
-		"grunt-contrib-concat": "~0.3.0",
-		"grunt-contrib-uglify": "~0.2.0",
+		"grunt": "~0.4.5",
+		"grunt-cli": "~0.1.13",
+		"grunt-contrib-jshint": "~0.11.0",
+		"grunt-contrib-concat": "~0.5.1",
+		"grunt-contrib-uglify": "~0.8.0",
 		"grunt-contrib-qunit": "~0.3.0",
-		"grunt-contrib-watch": "~0.5.3"
+		"grunt-contrib-watch": "~0.6.1"
 	},
 	"scripts": {
 		"test": "grunt travis --verbose"