Use bravado-asyncio as default HTTP client

[sjaensch]

This removes the duplicate implementation; I'm also doing some minor documentation fixes.

[coveralls]

Coverage decreased (-1.2%) to 96.287% when pulling dfacf26 on use-bravado-asyncio into 2cce48f on master.

[coveralls]

Coverage decreased (-1.2%) to 96.287% when pulling dfacf26 on use-bravado-asyncio into 2cce48f on master.

[macisamuele]

Really nice change 👍
🚢

[macisamuele]

Checking coverage data I see that no tests touch http_client.py.
I would suggest to add tests for that or to nuke it

[sjaensch]

I'd nuke it if we remove all code that we can just reuse from bravado. If I delete it it will just cause merge conflicts if the file ever changes upstream. Also it keeps the promise that in your code you can move from bravado to aiobravado, without having to know which modules are where.