Atrules update - Purge @font-face, Small refactor

[jsnanigans]

Proposed changes

Only use one .walk to do everything,

• check if its a normal rule or a atRule - line 250
• if its a normal rule then run the existing check, evaluateRule and if the rule is not removed then record the relevant declarations - line 309 to 322
• if its a atRule then register it for later regerence - line 256

after that there are two simple for loops that remove the keyframes and the font-faces, line 150 and 164

There might be a bug if someone uses the css font: 'My Fam' 20px because I only check for font-family: 'My Fam' because im not sure how to handle it if there are quotes around the name.

also #41 is fixed

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[Ffloriel]

Great PR! Thanks a lot.
Looks good to me. I just think it is better to keep the options in camelCase.

[jsnanigans]

Sure, did the changes