Added sin, cos, ata2. For details, see LOCAL_CHANGES.md.

Fix invalid YAML in .travis.yml (sass#887)

This also adds a test to verify that all YAML files are valid. Travis
won't run tests at all if its YAML is invalid, but this way Appveyor
can warn about broken Travis config and vice versa, and a local test
run will warn about either.

Merge pull request sass#884 from sass/fix-release

Fix release infrastructure for Dart 2.6

Fix inline comments in the indented syntax (sass#881)

Closes sass#880

Merge pull request sass#869 from sass/second-law-use

Propagate selector source specificity between modules

Don't compile .css files in directories to themselves (sass#862)

This also adds support for compiling .css files in directories *at
all*, which had previously only worked in --watch mode.

Closes sass#853

Run against Node 12 rather than Node 13 (sass#859)

This works around laverdet/node-fibers#420

Merge pull request sass#835 from sass/merge-use

Merge and enable feature.use 🎉

Merge pull request sass#820 from sass/release

Release 1.22.12

Tag 1.23.0-module.beta.1