Prepare to publish for stable null safety (#71)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c81256..599835f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 1.8.0
+
+* Stable release for null safety.
+
 # 1.8.0-nullsafety.4
 
 * Update SDK constraints to `>=2.12.0-0 <3.0.0` based on beta release
@@ -12,7 +16,7 @@
 # 1.8.0-nullsafety.2
 
 * Revert unnecessary null check fix (sdk fix wont land in 2.10 stable).
-* Allow 2.10 stable and 2.11 dev sdks. 
+* Allow 2.10 stable and 2.11 dev sdks.
 
 # 1.8.0-nullsafety.1
 
@@ -23,7 +27,7 @@
 * Migrate to null safety.
   * Apis have been migrated to reflect the existing assumptions in the code
     and are not expected to be breaking.
-    
+
 # 1.7.0
 
 * Add a `SourceSpan.subspan()` extension method which returns a slice of an
diff --git a/pubspec.yaml b/pubspec.yaml
index a5db06e..c589022 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: source_span
-version: 1.8.0-nullsafety.4
+version: 1.8.0
 
 description: A library for identifying source spans and locations.
 homepage: https://github.com/dart-lang/source_span
@@ -8,10 +8,10 @@
   sdk: ">=2.12.0-0.0 <3.0.0"
 
 dependencies:
-  charcode: '>=1.2.0-nullsafety <1.2.0'
-  collection: '>=1.15.0-nullsafety <1.15.0'
-  path: '>=1.8.0-nullsafety <1.8.0'
-  term_glyph: '>=1.2.0-nullsafety <1.2.0'
+  charcode: ^1.2.0
+  collection: ^1.15.0
+  path: ^1.8.0
+  term_glyph: ^1.2.0
 
 dev_dependencies:
   test: ^1.16.0-nullsafety