clipPath triggers error but its ok

[shelldandy]

https://developer.mozilla.org/en/docs/Web/SVG/Element/clipPath

🦄

[shelldandy]

https://github.com/yaniswang/HTMLHint/wiki/Attr-lowercase

Removing because of this, sorry

[shelldandy]

Maybe tagname lowercase should take an array of exceptions too?

https://github.com/yaniswang/HTMLHint/wiki/Tagname-lowercase

[hacknug]

@Mike3run check #188 for that