Update release notes for 2.6
# Changelog
-## 2.6.0-rc2 (2016-12-20)
-
-#### Spec
- - Authorization: add support for repository classes
-
-#### Registry
- - Add policy configuration for enforcing repository classes
-
-
-## 2.6.0-rc1 (2016-10-10)
+## 2.6.0 (2017-01-18)
#### Storage
- S3: fixed bug in delete due to read-after-write inconsistency
- Improve catalog enumerate runtime
#### Registry
- - Override media type returned from `Stat()` for existing manifests
- Export `storage.CreateOptions` in top-level package
- Enable notifications to endpoints that use self-signed certificates
- Properly validate multi-URL foreign layers
- Manifest: `References()` returns all children
- Honor `X-Forwarded-Port` and Forwarded headers
- Reference: Preserve tag and digest in With* functions
+- Add policy configuration for enforcing repository classes
#### Client
- Changes the client Tags `All()` method to follow links
#### Spec
- Manifest: clarify relationship between urls and foreign layers
+- Authorization: add support for repository classes
#### Manifest
+- Override media type returned from `Stat()` for existing manifests
- Add plugin mediatype to distribution manifest
#### Docs
-
- Document `TOOMANYREQUESTS` error code
- Document required Let's Encrypt port
- Improve documentation around implementation of OAuth2
+- Improve documentation for configuration
#### Auth
- Add support for registry type in scope
