Removing http & https web request library dependencies

[gaodeng]

Most projects using this library should already have their own network request library, so there doesn't seem to be much need to add the parseURL API. I suggest removing this method to remove the web request library dependency

[rbren]

This seems like a good idea to me. The HTTP logic has caused a lot of issues.

[eviltik]

https://github.com/rbren/rss-parser/pull/228