roadmap: update roadmap

ROADMAP.md

@@ -8,18 +8,21 @@ The dates below should not be considered authoritative, but rather indicative of
 
 etcd 2.0 is our current stable branch. The roadmap below outlines new features that will be added to etcd, and while subject to change, define what future stable will look like.
 
-### etcd 2.2
+### etcd 2.2 (September)
 - Improve client libraries
   - Go
-  - Python
-  - Java
+- Improve documentation
 - etcdctl
+  - use new etcd client
 - Stats and Metrics
   - Standardize endpoint for gathering metrics
   - Health and status endpoints
 - Add benchmarks for our future targets
+- V3 API preview
+  - non-clustered version
+  - support gRPC based key API
 
-### etcd 3.0
+### etcd 3.0 (January)
 - v3 API ([see also the issue tag](https://github.com/coreos/etcd/issues?utf8=%E2%9C%93&q=label%3Av3api))
   - Transactions
   - Leases