Add deployments feature to builder tool

[njgheorghita]

What was wrong?

Manifest builder tool needed some functions to facilitate adding a deployment to a manifest

How was it fixed?

added a deployment function, which simply allows you to pass in the desired deployment data

also added a deployment_type() function, which is slightly more complex, but allows for managing the same deployment across different chains, and some tx_receipt validation

Cute Animal Picture

[njgheorghita]

@pipermerriam ping for review. unsure how I feel about the deployment_type concept. i'm open to scrapping it temporarily, leaving only the simple deployment fn, and revisiting any w3-related validation post-devcon workshop