Using Program and attempting to --dry-run throws an exception

[dogonthehorizon]

When using a signal_analog.flow.Program one would expect that --dry-run would spit out the configuration for whatever resource we're creating. Instead we're treated with a nasty error:

TypeError: Object of type 'Program' is not JSON serializable

This shouldn't happen!

A good approach is going to be to make sure that whenever we call dry-run all resources have been properly serialized (e.g. Program should be turned into a string before printing)