Update node.js coverage, dependencies and potential issue

[steven-supersolid]

Restore test coverage - this had dropped a little with previous changes

Fix potential issue - Adding tests showed that all error messages were being captured in watchGameServer. I don't believe this was the original intention of the previous change but if it was then we can now modify the test and code accordingly

Update dependencies - the two dependencies have updates which fix security warnings and this removes the need for including the sub-dependency

Apply consistent style - I was trying to avoid style rules but the original code was written with some rules in mind that aren't covered by eslint:recommended

Ensure the example exits when an error is thrown

[agones-bot]

Build Succeeded 👏

Build Id: 3c5dddcc-0da9-4e43-9cfa-2c24cfb5c3c8

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:0.12.0-b836268
• image: gcr.io/agones-images/agones-sdk:0.12.0-b836268
• image: gcr.io/agones-images/agones-ping:0.12.0-b836268
• Linux C++ SDK (build): agonessdk-0.12.0-b836268-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-0.12.0-b836268.zip

A preview of the website (the last 30 builds are retained):

• https://b836268-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/GoogleCloudPlatform/agones.git pull/954/head:pr_954 && git checkout pr_954
• helm install install/helm/agones --namespace agones-system --name agones --set agones.image.tag=0.12.0-b836268

[markmandel]

This looks fine to me - but I'm no judge of node. Going to push it through so we can get the security fix in place.

Looks like mostly syntactic, formatting and test changes. 👍