Prepare to publish (dart-lang/json_rpc_2#78)

pkgs/json_rpc_2/CHANGELOG.md

diff --git a/pkgs/json_rpc_2/CHANGELOG.md b/pkgs/json_rpc_2/CHANGELOG.md
index 6a819f8..d28d50f 100644
--- a/pkgs/json_rpc_2/CHANGELOG.md
+++ b/pkgs/json_rpc_2/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 3.0.1-dev
+## 3.0.1
 
 * Fix a bug where a `null` result to a request caused an exception.
 

pkgs/json_rpc_2/pubspec.yaml

diff --git a/pkgs/json_rpc_2/pubspec.yaml b/pkgs/json_rpc_2/pubspec.yaml
index 4e1b8a3..f7217f6 100644
--- a/pkgs/json_rpc_2/pubspec.yaml
+++ b/pkgs/json_rpc_2/pubspec.yaml
@@ -1,5 +1,5 @@
 name: json_rpc_2
-version: 3.0.0
+version: 3.0.1
 description: >-
   Utilities to write a client or server using the JSON-RPC 2.0 spec.
 homepage: https://github.com/dart-lang/json_rpc_2