Allow null-safe pkg:yaml (dart-lang/pubspec_parse#62)

Prepare to release v0.1.7
diff --git a/pkgs/pubspec_parse/CHANGELOG.md b/pkgs/pubspec_parse/CHANGELOG.md
index f7a1a3a..26b1d31 100644
--- a/pkgs/pubspec_parse/CHANGELOG.md
+++ b/pkgs/pubspec_parse/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.1.7
+
+- Allow `package:yaml` `v3.x`.
+
 ## 0.1.6
 
 - Update SDK requirement to `>=2.7.0 <3.0.0`.
diff --git a/pkgs/pubspec_parse/pubspec.yaml b/pkgs/pubspec_parse/pubspec.yaml
index 6e2a7e9..5cda976 100644
--- a/pkgs/pubspec_parse/pubspec.yaml
+++ b/pkgs/pubspec_parse/pubspec.yaml
@@ -2,7 +2,7 @@
 description: >-
   Simple package for parsing pubspec.yaml files with a type-safe API and rich
   error reporting.
-version: 0.1.6
+version: 0.1.7
 repository: https://github.com/dart-lang/pubspec_parse
 
 environment:
@@ -13,7 +13,7 @@
   # Verified that no new features since 1.0.0 are used - be careful!
   json_annotation: '>=1.0.0 <5.0.0'
   pub_semver: ^1.3.2
-  yaml: ^2.1.12
+  yaml: '>=2.1.12 <4.0.0'
 
 dev_dependencies:
   build_runner: ^1.0.0