Fix/tests (react-grid-layout#908)

* fix(test): fix jsdom error w/jest

* fix(test): ensure TimSort in Node 11+ doesn't break our tests

The test shouldn't depend on the runtime's Array#sort internals

package.json

@@ -86,7 +86,8 @@
   "jest": {
     "testMatch": [
       "<rootDir>/test/spec/*.js"
-    ]
+    ],
+    "testURL": "http://localhost"
   },
   "lint-staged": {
     "*.{js,jsx}": [

test/spec/utils-test.js

@@ -398,14 +398,14 @@ describe("compact horizontal", () => {
   it("Handles recursive collision by moving new collisions out of the way before moving item to the right", () => {
     const layout = [
       { y: 0, x: 0, h: 2, w: 5, i: "1" },
-      { y: 0, x: 0, h: 10, w: 1, i: "2" },
+      { y: 1, x: 0, h: 10, w: 1, i: "2" },
       { y: 5, x: 1, h: 1, w: 1, i: "3" },
       { y: 5, x: 2, h: 1, w: 1, i: "4" },
       { y: 5, x: 2, h: 1, w: 1, i: "5", static: true }
     ];
     expect(compact(layout, "horizontal", 10)).toEqual([
       { y: 0, x: 0, h: 2, w: 5, i: "1", moved: false, static: false },
-      { y: 0, x: 5, h: 10, w: 1, i: "2", moved: false, static: false },
+      { y: 1, x: 5, h: 10, w: 1, i: "2", moved: false, static: false },
       { y: 5, x: 6, h: 1, w: 1, i: "3", moved: false, static: false },
       { y: 5, x: 7, h: 1, w: 1, i: "4", moved: false, static: false },
       { y: 5, x: 2, h: 1, w: 1, i: "5", moved: false, static: true }