Update pubspec.yaml
Update pubspec.yaml

Pick up a bug fix to the `usage` package.
flutter/flutter,cbracken/flutter,cbracken/flutter,turnidge/flutter,tvolkert/flutter,flutter/flutter,aghassemi/flutter,cbracken/flutter,Hixie/flutter,aghassemi/flutter,turnidge/flutter,tvolkert/flutter,aghassemi/flutter,cbracken/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,turnidge/flutter,tvolkert/flutter,tvolkert/flutter,Hixie/flutter,cbracken/flutter,turnidge/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,turnidge/flutter,cbracken/flutter,tvolkert/flutter,flutter/flutter,cbracken/flutter,flutter/flutter,tvolkert/flutter,tvolkert/flutter,flutter/flutter,Hixie/flutter,cbracken/flutter,aghassemi/flutter,flutter/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,cbracken/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter