Prevent check command running if module can't execute

Fixes #10

Author: rastating

lib/cli/loaded_module.rb

@@ -45,7 +45,7 @@ def run
     end
 
     def check
-      return unless module_loaded?
+      return unless module_loaded? && module_can_execute?
       state = context.module.check
 
       if state == :vulnerable