Add timeout parameter to requests calls because they can hang forever…

[Xangis]

Add timeout parameter to requests calls because they can hang forever if the connection does not close properly.

I've been using this modified version for my own icon harvesting script and the addition of the timeout parameter prevents hangs.

You may want to adjust the timeout, but 20 seconds has worked well enough for me.

[scottwernervt]

@Xangis Thanks for the PR but the timeout value should be left up to the user of this package. We provide an example in the README for setting timeout arg:

Request library parameters can be passed to favicon.get() as keyword arguments:
...
favicon.get('https://www.python.org/', headers=headers, timeout=2)

Maybe instead we can add a note to the README to set it if you are experiencing hangs.

[Xangis]

Sure, a note would be good. Requests recommends never calling it without a timeout value because it can hang infinitely, so I figured having some sort of default, even if it's ridiculously long, would prevent nasty surprises.