Parse Channel URL and get channel ID or username

[ashwanipathak]

Added parseChannelIdFromUrl($url) function to parse URL and return the channel ID or username from the URL.

[sokai]

@madcoda Hey, may I try to ask you to merge this feature, plz?

As you can see in the travis-ci log here the job only failed because PHP 5.3 is not supported by travis, the rest is fine … 🙄

So, I like the feature and the code quality may be good. Thanks + KR