Update dependencies for stable null-safety release (#29)

Co-authored-by: Kevin Moore <kevmoo@users.noreply.github.com>
diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 8d80674..3a2924f 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -24,7 +24,7 @@
       - uses: dart-lang/setup-dart@v1.0
         with:
           sdk: ${{ matrix.sdk }}
-      - run: pub get
+      - run: dart pub get
       - run: dart format --output=none --set-exit-if-changed .
       - run: dart analyze --fatal-infos
       - run: dart test
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8e54714..f8c9e75 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,11 @@
+## 2.0.0
+
+- Stable null safety release.
+
 ## 2.0.0-nullsafety.0
 
-- Upgrade to sound null safety
-- Require Dart 2.12.0-0
+- Upgrade to sound null safety.
+- Require Dart 2.12.0-0.
 
 ## 1.0.3
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 7c2e1aa..45d291b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,15 +1,15 @@
 name: tuple
-version: 2.0.0-nullsafety.0
+version: 2.0.0
 
 description: Tuple data structure
 repository: https://github.com/google/tuple.dart
 
 environment:
-  sdk: '>=2.12.0-0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
-  quiver: ^3.0.0-nullsafety
+  quiver: ^3.0.0
 
 dev_dependencies:
-  pedantic: ^1.10.0-nullsafety
-  test: ^1.16.0-nullsafety
+  pedantic: ^1.10.0
+  test: ^1.16.0