[FEATURE] Creating, Submitting, and Handling IPUMS Data Extracts

[TheCedarPrince]

This PR introduces the following features through a variety of modifications and new functionalities added:

• Submit an extract request
• Download an extract
• Find out information about an extract
• Convenience wrapper for creating an API object (done out of crankiness)

It encompasses documentation, tests, and these features.

[TheCedarPrince]

Hey @00krishna , the good news is is that this branch is ready for review! There are a lot of changes I introduced mostly with regards to documentation and the API for extracts, but the new and improved API is this to submit and work with extracts:

using IPUMS

api = IPUMSAPI("https://api.ipums.org/", Dict("Authorization" => "Your_Key"))

test_extract_definition = "test/testdata/example_extract_request.json"

res = extract_submit(api, "nhgis", test_extract_definition)

metadata, defn, msg = extract_info(api, res.number, "nhgis")

extract_list(api, "nhgis", "2")

Let me know what you think and how it works for you!

The big question here is I don't know how best to test these features. Do you have any ideas/suggestions?

[00krishna]

Hey Jacob. I looked over the code and it look good. I just made a few small comments about content, but nothing major.

The api looks good. I suppose as we practice with it, we can always polish it.

In terms of testing, that is a good question. I think the download functionality itself is tested by the OpenAPI.jl package folks. You could try and save a local file to the test directory, and then try to download locally? That is one way to do it. Meaning you really only need to test everything after the download.