Replace deprecated electron-prebuilt with electron@2.0.18

- Updated package.json to use electron@2.0.18 instead of electron-prebuilt@1.4.3
- Modified lib/jibo-cli.js to reference 'electron' instead of 'electron-prebuilt'
- This fixes compatibility issues with the simulator on modern Linux systems
- electron-prebuilt was deprecated and renamed to electron in 2016

node_modules/electron/cli.js

@@ -0,0 +1,21 @@
+#!/usr/bin/env node
+
+var electron = require('./')
+
+var proc = require('child_process')
+
+var child = proc.spawn(electron, process.argv.slice(2), {stdio: 'inherit', windowsHide: false})
+child.on('close', function (code) {
+  process.exit(code)
+})
+
+const handleTerminationSignal = function (signal) {
+  process.on(signal, function signalHandler () {
+    if (!child.killed) {
+      child.kill(signal)
+    }
+  })
+}
+
+handleTerminationSignal('SIGINT')
+handleTerminationSignal('SIGTERM')