Build: Update deps (except grunt), switch to lodash

Grunt update is blocked by jzaefferer/grunt-check-modules#5

Author: mgol

Gruntfile.js

@@ -1,6 +1,6 @@
 module.exports = function( grunt ) {
 
-var _ = require( "underscore" ),
+var _ = require( "lodash" ),
 	semver = require( "semver" ),
 	Handlebars = require( "handlebars" ),
 	http = require( "http" );

package.json

@@ -23,8 +23,8 @@
     "grunt": "0.4.5",
     "grunt-jquery-content": "3.0.1",
     "grunt-sri": "0.0.5",
-    "semver": "2.0.11",
-    "underscore": "1.5.1",
-    "handlebars": "1.0.12"
+    "handlebars": "4.0.5",
+    "lodash": "4.12.0",
+    "semver": "5.1.0"
   }
 }