Prepare to publish (#117)

diff --git a/pubspec.yaml b/pubspec.yaml
index 06e2305..a65ec98 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: matcher
-version: 0.12.6-dev
+version: 0.12.6
 
 description: >-
   Support for specifying test expectations via an extensible Matcher class.