chore(package): update @types/node to version 8.0.6

Closes #38

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
   "homepage": "https://github.com/DxCx/rxjs-diff-operator#readme",
   "devDependencies": {
     "@types/jest": "^19.2.2",
-    "@types/node": "^7.0.12",
+    "@types/node": "^8.0.6",
     "browserify": "^14.3.0",
     "delete-empty": "^1.0.1",
     "dts-bundle": "^0.7.2",