Merge pull request #54 from ericam/master

Add test for each loop with maps
Re-add specs for list_separator
Add libsass spec for parsing css variables
Add spec for the deep combinator
Add test for parsing error in SassScript Maps implementation -- libsass PR 481
Add test for multiple key removal functionality in map-remove(), as per Sass 3.4.x
Add test for multi-assignment in `@each`
rename issue 481 dir to issue 509
enable basic test 51: trailing commas
Add test for @at-root feature, issue 353
test for css directive ordering
Add test for nested media query combination. #185
Add test for falsey return value of index function
fix test 34 to expect suppressed null value
Merge pull request #62 from lunelson/issue-512

Add test for falsey return value of index function
Merge pull request #63 from lunelson/test-34

fix test 34 to expect suppressed null value
Merge pull request #61 from lunelson/issue-185

Add test for nested media query logical combination
Merge pull request #60 from lunelson/issue-469

Add test for css directive ordering
Merge pull request #59 from lunelson/issue-353

Add test for @at-root feature
Merge pull request #58 from lunelson/master

Tests for nested maps, map-remove, multi-assign...