Add nk tool

[jonaskello]

What motivated this proposal?

I was looking for a way to run the nk tool without directly installing it on my computer

What is the proposed change?

Add nk tool to the image

Who benefits from this change?

Anyone that does not have go installed since nk installation seems to require go.

What alternatives have you evaluated?

Installing go on my local computer and then installing the nk tool.

[jonaskello]

Seems like there was deb files published for nk so as an alternative to the go install you can do:

wget https://github.com/nats-io/nkeys/releases/download/v0.4.7/nkeys-v0.4.7-amd64.deb
sudo apt-get install ./nkeys-v0.4.7-amd64.deb

[gedw99]

Would be useful too