Add missing releases to Mynewt repository.yml

This make it possible to setup Mynewt project with latest releases.

repository.yml

@@ -9,7 +9,9 @@ repo.versions:
     "0.10.0": "0.10.0"
     "0.10.1": "0.10.1"
     "0.11.0": "0.11.0"
+    "0.12.0": "0.12.0"
+    "0.13.0": "0.13.0"
 
     "0-dev": "0.0.0"        # master
-    "0-latest": "0.11.0"     # latest stable release
+    "0-latest": "0.13.0"    # latest stable release