Prepare to publish for stable null safety (#168)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2dcf13c..f990411 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.12.10
+
+* Stable release for null safety.
+
 ## 0.12.10-nullsafety.3
 
 * Update SDK constraints to `>=2.12.0-0 <3.0.0` based on beta release
@@ -59,7 +63,7 @@
 
 - Many improvements to `TypeMatcher`
   - Can now be used directly as `const TypeMatcher<MyType>()`.
-  - Added a type parameter to specify the target `Type`. 
+  - Added a type parameter to specify the target `Type`.
     - Made the `name` constructor parameter optional and marked it deprecated.
       It's redundant to the type parameter.
   - Migrated all `isType` matchers to `TypeMatcher`.
@@ -217,7 +221,7 @@
 
 ## 0.10.0+3
 
-* Removed `@deprecated` annotation on matchers due to 
+* Removed `@deprecated` annotation on matchers due to
 [Issue 19173](https://code.google.com/p/dart/issues/detail?id=19173)
 
 ## 0.10.0+2
diff --git a/pubspec.yaml b/pubspec.yaml
index ac71c13..5667861 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: matcher
-version: 0.12.10-nullsafety.3
+version: 0.12.10
 
 description: >-
   Support for specifying test expectations via an extensible Matcher class.
@@ -10,7 +10,7 @@
   sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
-  stack_trace: '>=1.10.0-nullsafety <1.10.0'
+  stack_trace: ^1.10.0
 
 dev_dependencies:
   pedantic: ^1.10.0-nullsafety