Node v10.15.0 error

[Dirk Pennings]

Hi David, I decided to make this issue so you could see what the error was when I changed it to a member in the PR. Best Dirk

OS: macOS Mojave (10.14.2)
Node version: v10.15.0

➜  signalr-node-server git:(master) node app.js
signalr-ports/signalr-node-server/signalr.js:356
    _methods = new Map();
             ^

SyntaxError: Unexpected token =
    at new Script (vm.js:79:7)
    at createScript (vm.js:251:10)
    at Object.runInThisContext (vm.js:303:10)
    at Module._compile (internal/modules/cjs/loader.js:657:28)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Module.require (internal/modules/cjs/loader.js:637:17)
    at require (internal/modules/cjs/helpers.js:22:18)