JSON, YAML, and CSV output

[gtrevg]

This pull request adds in three more formatters (json, yaml, and csv) that can be controlled with the --format flag. The default is table.

[lebinh]

Looking good @gtrevg, thanks for the PR! However there seems to be some mixed up spaces and tabs. The current code are using spaces so can you please update to use the same and thus don't have to change unrelated parts in the commit diff?

[gtrevg]

@lebinh I'll fix the spacing so it's only spaces.

[gtrevg]

@lebinh The updates have been made and I added in YAML support as well.

Great tool, btw!