Throw error if app id is not given

[ajoslin]

I had this code:

function IonicConfig ($ionicAppProvider) {
  $ionicAppProvider.identify({
    app_id: env.ionicAppId,
    api_key: env.ionicApiKey
  })
}

My env didn't have ionicAppId and ionicApiKey, even though I thought it did. A stupid mistake.

But the undefined appId and apiKey were causing $ionicDeploy.checkUpdate() to crash my app.

Now the javascript will throw an error if app_id is undefined.