[js] Bump the minimum supported version of node to 8.9.0 LTS

Author: jleyba

javascript/node/selenium-webdriver/CHANGES.md

@@ -2,7 +2,7 @@
 
 ### Notice
 
-*  The minimum supported version of Node is now 8.6.0
+*  The minimum supported version of Node is now 8.9.0 LTS
 
 ### Changes to Supported Browsers
 

javascript/node/selenium-webdriver/package.json

@@ -20,7 +20,7 @@
     "url": "https://github.com/SeleniumHQ/selenium.git"
   },
   "engines": {
-    "node": ">= 8.6.0"
+    "node": ">= 8.9.0"
   },
   "dependencies": {
     "jszip": "^3.1.3",