Add CHANGELOG

Fixes #54

Author: pbrisbin

CHANGELOG.md

@@ -0,0 +1,32 @@
+## [*Unreleased*] https://github.com/codeclimate/spec/compare/v0.3.1...master
+
+- None
+
+## [v0.3.1] https://github.com/codeclimate/spec/compare/v0.3.0...v0.3.1
+
+- [CHANGED] Require `LABEL maintainer`, not `MAINTAINER`
+
+## [v0.3.0] https://github.com/codeclimate/spec/compare/v0.2.0...v0.3.0
+
+- [NEW] Minor, major, and blocker Issue severities
+
+- [CHANGED] Increased resource limits (image size, memory)
+
+- [REMOVED] Normal Issue severity
+
+## [v0.2.0] https://github.com/codeclimate/spec/compare/v0.1.0...v0.2.0
+
+- [NEW] Engine manifest description, languages, version
+- [NEW] Issue fingerprint
+- [NEW] Issue traces
+- [NEW] Performance Issue category
+
+- [CHANGED] List of permitted languages
+- [CHANGED] Increase example Issue remediation_points value
+- [CHANGED] Issue location structure
+
+- [REMOVED] Engine configuration exclude_paths
+
+## [v0.1.0] https://github.com/codeclimate/spec/tree/v0.1.0
+
+- [NEW] Initial release