Fix processing rules with additional appended classes, i.e. &.someclass

[asvetliakov]

What:
Fix the output when css rule have only something like this:

  &.active {
    background:green;
  }

Previously it was skipped from output due to wrong filtering in getStyles()

How:
See getStyles in serializer.js in PR

[codecov]

Codecov Report

Merging #22 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #22   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           2      2           
  Lines          65     66    +1     
  Branches       13     14    +1     
=====================================
+ Hits           65     66    +1

Impacted Files	Coverage Δ
src/serializer.js	100% <100%> (ø)	⬆️

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[kentcdodds]

Looks good to me! Thank you 👍

[kentcdodds]

Would you like to add yourself to the contributors table?

[kentcdodds]

Thanks so much for your help! I've added you as a collaborator on the project. Please make sure that you review the other/MAINTAINING.md and CONTRIBUTING.md files (specifically the bit about the commit messages and the git hooks) and familiarize yourself with the code of conduct (we're using the contributor covenant). You might also want to watch the repo to be notified when someone files an issue/PR. Please continue to make PRs as you feel the need (you can make your branches directly on the repo rather than your fork if you want). Thanks! And welcome to the team :)

[asvetliakov]

Thanks! I'll add myself to the table