exclude vendor directory in dart analyze

Author: chrisirhc

analysis_options.yaml

@@ -9,6 +9,9 @@
 # packages, and plugins designed to encourage good coding practices.
 include: package:flutter_lints/flutter.yaml
 
+analyzer:
+  exclude: [vendor/**]
+
 linter:
   # The lint rules applied to this project can be customized in the
   # section below to disable rules from the `package:flutter_lints/flutter.yaml`