Clean up spec dir, name files correctly

[enriclluelles]

Hi, I was working on implementing keyframes recognition on libsass and found out that there was a mistake in spec.rb and some of the files used for comparing output were not named correctly, so I fixed it.

Cheers

[HamptonMakes]

Thanks for this. I noticed the same thing today.... and seems like 4 different people all fixed this at the same time! Merging this stuff is a headache, so I'm just going to close this one since the work was pulled in from other tickets. But, seriously, thanks for helping out with the project, sorry for the slow response time. Really need people to help though. It's a big project! These specs are what are going to form the main Sass test suite for all implementations, so we need all the help we can get!