Added basic property tests for matchersUtil.equals

* See #1764 from @dubzzz
* Property tests are only run in Node, not browser.
* The Travis build sets JASMINE_LONG_PROPERTY_TESTS to enable much more
  thorough (but slow) testing.

package.json

@@ -30,6 +30,7 @@
     "ejs": "^2.5.5",
     "eslint": "^5.16.0",
     "express": "^4.16.4",
+    "fast-check": "^1.21.0",
     "fast-glob": "^2.2.6",
     "grunt": "^1.0.4",
     "grunt-cli": "^1.3.2",