Does not work well with materializecss

[rolandstarke]

Hey,

I always wondered why backdropHeight did not work. (the backdrop images where not visible).
I am using materializecss and it looks like they apply their own styles to .backdrop.

https://github.com/Dogfalo/materialize/blob/c9363571a1fe60168d3833bf2b139b52723b5b04/sass/components/_tooltip.scss#L22-L32

edit: they also overwrite .carousel
https://github.com/Dogfalo/materialize/blob/c9363571a1fe60168d3833bf2b139b52723b5b04/sass/components/_carousel.scss

[tjenkinson]

hmm interesting. Feel free to open a pr changing the class name to something more specific