message: update immutable.js to v3.8.2 (MIT license)
diff: "datamaps": "^0.5.8",
  "datatables.net-bs": "^1.10.15",
  "distributions": "^1.0.0",
  - "immutable": "^3.8.1",
  + "immutable": "^3.8.2",
  "jed": "^1.1.1",
  "po2json": "^0.4.5",
  "jquery": "3.1.1",
  