Support for peer hostAliases in create and update

[minollo]

• Let users specify host aliases, so that /etc/hosts on peer containers can be easily managed. Peers need to be able to resolve the ordering node names - needed when using Istio and no real DNS.
• Introduce peer update command - for now to let users change host aliases even after the peer has been created.

[adityajoshi12]

Q: updating the /etc/hosts file is not a good way, let's think of a better way to enable communication between peers and orderer, Kubernetes services could be one of the ways.

[minollo]

Surely not something you would want to use in production systems; but it is something which makes testing/prototyping with k8s/istio clusters where nodes are private easy. Using k8s hostAliases - as I did here - it abstracts users from what happens (/etc/hosts) under the cover.

[dviejokfs]

Thanks for the PR! Could you implement the same for the orderer nodes?

Also, please, you need to complete the DCO; you can execute the following commands to resolve it:

git rebase --signoff HEAD~10
git push --force

[minollo]

Sure, I'll do the same for ordering nodes tomorrow. I have executed the git commands you suggested.

[minollo]

Added hostAliases support to ordnodes. The code base seems to be in dire need of UTs...

[dviejokfs]

I'm merging the PR, thank you so much @minollo!