Automate deployment of Clarity scripts

[jbencin]

Currently, deploying a new version of the subnet contract requires a lot manual steps:

• Deploy subnet.clar to dev, stg, and prod
• Deploy multi-miner.clar to dev, stg, and prod
• Make 2 contract calls on each subnet deployment

That's a total of 12 transactions, and making a mistake could mean that the whole process needs to be restarted. This process should be automated with a Node script using Stacks.js