add support for mirrors for fedora

[hbarsaiyan]

Added support for fetching mirrorlists from https://mirrors.fedoraproject.org/mirrorlist. Now we iterate through all the directories and when a connection is closed, we continue iterating using the next mirror.

Fixes #191 for now. Although, I am working on a more generalized solution to use mirrors for all supported distros and make the requests async, which will be a permanent solution.

[pleia2]

I left a comment in the issue because this approach requires further discussion.