feat: Add logs for kubelet non-ready nodes

[ryanjkemper]

This PR resolves two issues I've seen while using this application:

First, on some larger clusters we would see:

ASG has X non-ready updated nodes/instances, waiting until all nodes/instances are ready  

However, this would run in a loop with no indication of which instances were not ready even though according to kubectl, it seemed that all instances were ready. Adding another log line to report which instances were not ready helps aid in troubleshooting nodes that are not ready for long periods of time.

---

Second, it adds git to the Dockerfile else, docker builds fail for me with the following error:

Step 4/9 : RUN CGO_ENABLED=0 GOOS=linux go build -mod vendor -a -installsuffix cgo -o aws-eks-asg-rolling-update-handler .
 ---> Running in 79e131118b89
go: missing Git command. See https://golang.org/s/gogetcmd
error obtaining VCS status: exec: "git": executable file not found in $PATH
        Use -buildvcs=false to disable VCS stamping.
The command '/bin/sh -c CGO_ENABLED=0 GOOS=linux go build -mod vendor -a -installsuffix cgo -o aws-eks-asg-rolling-update-handler .' returned a non-zero code: 1

[ryanjkemper]

I've made your suggested updates and tested that the Dockerfile still builds. I can test the node rolling status we were issuing within the next week or two as I run it against our clusters again.

Failing check

[ryanjkemper]

@TwiN Thanks for the merge!

Is there a schedule when a new release/docker hub image will be cut? Looks like latest may be updated, but generally don't like using latest tag

[TwiN]

Thank you for the contribution!

I've just released v1.3.0 for you, sorry for the delay :)