Build: Upgrade grunt-git-authors to 3.1.0

Ref jquerygh-1670

Author: scottgonzalez

Gruntfile.js

@@ -378,7 +378,7 @@ grunt.initConfig({
 });
 
 grunt.registerTask( "update-authors", function() {
-	var getAuthors = require( "grunt-git-authors" ),
+	var getAuthors = require( "grunt-git-authors" ).getAuthors,
 		done = this.async();
 
 	getAuthors({

package.json

@@ -62,7 +62,7 @@
 		"grunt-contrib-qunit": "1.0.1",
 		"grunt-contrib-requirejs": "0.4.4",
 		"grunt-contrib-uglify": "0.11.1",
-		"grunt-git-authors": "2.0.0",
+		"grunt-git-authors": "3.1.0",
 		"grunt-html": "4.0.1",
 		"grunt-jscs": "2.1.0",
 		"load-grunt-tasks": "0.3.0",