Update ws to v5

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 This contains only the most important and/or user-facing changes; for a full changelog, see the commit history.
 
+## [1.0.17](https://github.com/ably/ably-js/tree/1.0.17) (in progress)
+
+Note: this release drops support for node 4 version below 4.5. Customers using node v4 are highly encouraged to update to the latest 4.x branch, for security reasons.
+
 ## [1.0.16](https://github.com/ably/ably-js/tree/1.0.16) (2018-06-25)
 
 - Ensure a message id is included when serialized (https://github.com/ably/ably-js/pull/518)

README.md

@@ -8,7 +8,7 @@ This SDK supports the following platforms:
 
 **Browsers:** All major desktop and mobile browsers, including (but not limited to) Chrome, Firefox, IE (only version 8 or newer), Safari on iOS and macOS, Opera, and Android browsers.
 
-**Node.js:** version 4 or newer
+**Node.js:** version 4.5 or newer
 
 **React Native:** see [ably-js-react-native](https://github.com/ably/ably-js-react-native)
 

package.json

@@ -13,7 +13,7 @@
   "dependencies": {
     "msgpack-js": "https://github.com/ably-forks/msgpack-js.git",
     "request": "^2.87.0",
-    "ws": "~4.0"
+    "ws": "^5.1"
   },
   "devDependencies": {
     "async": "git://github.com/ably-forks/async.git#requirejs",
@@ -46,7 +46,7 @@
     "shelljs": "~0.3"
   },
   "engines": {
-    "node": ">=4.2.x"
+    "node": ">=4.5.x"
   },
   "repository": {
     "type": "git",