Fix pkg:test dependency (#34)

diff --git a/pubspec.yaml b/pubspec.yaml
index dccc19b..51a8048 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -10,4 +10,4 @@
 dependencies:
   typed_data: "^1.0.0"
 dev_dependencies:
-  test: "^0.12.0"
+  test: ^1.0.0