Build: Upgrade grunt-bowercopy to 1.2.4

Ref gh-1670

Author: scottgonzalez

package.json

@@ -54,7 +54,7 @@
 	"devDependencies": {
 		"commitplease": "2.0.0",
 		"grunt": "0.4.5",
-		"grunt-bowercopy": "1.1.0",
+		"grunt-bowercopy": "1.2.4",
 		"grunt-compare-size": "0.4.0",
 		"grunt-contrib-concat": "0.5.1",
 		"grunt-contrib-csslint": "0.2.0",