Merge pull request #6 from Polymer/release-pr/v1.2.0

prepare changelog for release

CHANGELOG.md

@@ -7,9 +7,15 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased - Breaking Changes
 
+## [1.2.0] - 2017-01-27
+
+* Added `isSources()` method to ProjectConfig: validates that a given file path matches the project's "sources" globs. Useful for determining if a file should be treated as a source file or as a dependency.
+* New Config Option: `builds` defines project build configurations.
+* `validate()` now checks the `builds` property for missing and duplicate names.
+
 ## [1.1.0] - 2016-12-09
 
-* Added `validate()` function, to validate that polymer.json contains valid paths.
+* Added `validate()` method to ProjectConfig: validates that polymer.json contains valid paths.
 
 ## [1.0.2] - 2016-09-23