fix genius implementation; other changes

[brenol]

Hi! I made a few small changes to improve LyricApi.

I think the idea is very nice but there are a few other cases that I did not handle in this pull-request:

• There are many log.Fatal lines all over the library - those should be removed because they would make the application to abort completely; making lyric-api only useful for those that wouldn't use in long-running programs. I did not make the change to all those log.Fatal lines because that would break the API compatibility (returning an error).

• I made a few small changes in how goquery was being used just to remove a few lines of code

• I fixed the Genius implementation as fetch was always looking for "John Lennon - Imagine"

The idea is very nice though; hope I helped to improve it a little bit.

[rhnvrm]

@brenol - Thanks for the PR. Just a few points,

1. https://godoc.org/github.com/PuerkitoBio/goquery#NewDocument says that it is deprecated. It would be better to not use it and keep the current implementation and stick to bytes for now. I am planning to allow passing the net/http config to the New function to help reuse it.
2. The changes for "remove unused line" and L78 (https://github.com/rhnvrm/lyric-api-go/pull/1/files#diff-cfad0e134601aa73999ff0ae5c44bf71R78) LGTM.

Please send a squashed commit with the changes mentioned in 2.

Thank you.

I will add a test for lyrics.go after your PR is merged along with removing log.fatal lines (thanks for pointing that out, I had missed this).

Regards

[brenol]

Oh! Sorry, I did not know that NewDocument was being deprecated since I've been using it for a long time for some quick stuff.

I'll modify the PR and send it over with everything correctly. Thanks for pointing that out!

[brenol]

OK, think I squashed correctly. Really really not used to doing rebases and push -force.

Thanks!

[rhnvrm]

@brenol LGTM, have merged the changes! Thanks for your contribution. :+1: