Add tests for by_two function and improve

[M3rs]

Add basic tests for by_two function: empty input, even and odd length input.

Refactor by_two function to return more explicit namedtuple with items (url, data).

[M3rs]

Pros/Cons of namedtuple:

(could probably rename it to something like release_info, based on use)

Code in count_downloads could look more like:

for release_info in get_release_info([package], json=json):
    for url in release_info.urls:
        # etc

Here is a talk by Raymond Hettinger (https://www.youtube.com/watch?v=wf-BqAjZb8M), towards the end he talks about how nametuples are great.

Pros:

• Adds clarity (each time it is used, the values urls, data are pulled from it)
• tuples are immutable (before was returning a list)
• provides access fields vs unpacking / indexing

Cons:

• Admittedly, I am having trouble finding any.

[hugovk]

Ha, I was just watching that video and had it paused! namedtuple bit is at here and makes sense.

Would you like to resolve the merge conflict?

[M3rs]

Resolved merge conflicts

[hugovk]

Thanks!