Prepare to publish for stable null safety (#25)

Author: natebosch

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.1.0
+
+* Stable release for null safety.
+
 ## 2.1.0-nullsafety.4
 
 * Update SDK constraints to `>=2.12.0-0 <3.0.0` based on beta release

pubspec.yaml

@@ -1,15 +1,15 @@
 name: source_map_stack_trace
-version: 2.1.0-nullsafety.4
+version: 2.1.0
 description: A package for applying source maps to stack traces.
 homepage: https://github.com/dart-lang/source_map_stack_trace
 
 environment:
   sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
-  path: '>=1.8.0-nullsafety <1.8.0'
-  stack_trace: '>=1.10.0-nullsafety <1.10.0'
-  source_maps: '>=0.10.10-nullsafety <0.10.10'
+  path: ^1.8.0
+  stack_trace: ^1.10.0
+  source_maps: ^0.10.10
 
 dev_dependencies:
   source_span: ^1.8.0-nullsafety