Enable STAC Output for GranuleQuery

[scottyhq]

Address #81

Basic usage:

api = GranuleQuery() 
search = api.parameters(
    point=(-105.78, 35.79),
    temporal=('2021-02-01','2021-03-01'),
    collection_concept_id='C2021957657-LPCLOUD'  # collection_concept_id required for STAC search
)
items = search.format("stac").get()

[chuckwondo]

@scottyhq, thanks for your submission! Please see my comments, and please also add an entry to CHANGELOG.md.

[chuckwondo]

Great! Thank you!