Enable no-unused-vars and fix eslint errors

specs/.eslintrc.json

@@ -2,8 +2,5 @@
     "extends": "../.eslintrc.json",
     "env": {
         "jasmine": true
-    },
-    "rules": {
-        "no-unused-vars": "off"
     }
 }

specs/lib/obj2gltfSpec.js

@@ -5,7 +5,6 @@ var os = require('os');
 var path = require('path');
 var Promise = require('bluebird');
 var obj2gltf = require('../../lib/obj2gltf');
-var writeUris = require('../../lib/writeUris');
 
 var objPath = 'specs/data/box-textured/box-textured.obj';
 var gltfPath = 'specs/data/box-textured/box-textured.gltf';

specs/matchers/addDefaultMatchers.js

@@ -1,6 +1,7 @@
 //This file is a copy of https://github.com/AnalyticalGraphicsInc/cesium/blob/master/Specs/addDefaultMatchers.js
 /*eslint strict: ["error", "function"]*/
 /*eslint-env amd*/
+/*eslint-disable no-unused-vars*/
 define([
         './equals',
         'Cesium/Core/defined',