Add optional flag that compresses run file

A `--compress` flag can be added to the `run-build` command, such that the `run.json` file is compressed. `gzip` ([examples](https://docs.python.org/3/library/gzip.html#examples-of-usage) can be used to compress the run.json file. 

### Acceptance
* `--compress` flag is introduced
* e2e tests
* man page is updated
