add tests for not expressions
better css formatter
fix skip option and set default
add examples
clean up options some more
Moved extend test 190 out of todo, added test of @extend output.
Removed basic-extend-tests, as they are duplicated in extend-tests.
add tests for CSS native filter functions

Add tests to verify that attempts to use native CSS filter functions,
like `grayscale(20%)`, are properly passed through to CSS unchanged,
rather than interpreted as the Sass function `grayscale` that operates
on colors.

Fixes compatibility with Ruby Sass.
exit with failure code when minitest fails

This is causing Travis to report false positives. Ahh!

See: sass/libsass#468.
Merge pull request #36 from benesch/report-failures

exit with failure code when minitest fails
Merge pull request #30 from blopker/master

Fix --skip option and add a more consistent CSS formatter.
Merge remote-tracking branch 'michaek/feature/remove-basic-extend-tests'
Merge remote-tracking branch 'michaek/feature/placeholder-grouped-selector'

Conflicts:
	spec/extend-tests/190_test_semi_placeholder_selector/input.scss
Moved passing extend tests out of todo folder.
Added placeholder-with-media test case.
Removed spec/scss-old, as diff -r showed no changes from spec/scss.
Removed spec/todo/scss-old.
Disabled tests that cause fatal errors in Ruby Sass.

Set explicit Sass version in Gemfile.
Added note to Readme about renaming test cases.
Disabled tests of functions not defined in Sass 3.2.
Made test name more obviously reflect directory structure.