Switch from homepage to repository in pubspec (#54)

pubspec.yaml

diff --git a/pubspec.yaml b/pubspec.yaml
index b891448..60573f1 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -2,7 +2,7 @@
 version: 4.0.2-dev
 description: >-
   A platform-independent package for parsing and serializing HTTP formats.
-homepage: https://github.com/dart-lang/http_parser
+repository: https://github.com/dart-lang/http_parser
 
 environment:
   sdk: '>=2.12.0 <3.0.0'