LameSkipConvention.cs

[AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = false)]
public class SkipAttribute : Attribute { }

public class CustomConvention : Convention
{
    public CustomConvention()
    {
        Classes
            .NameEndsWith("Tests");

        Methods
            .Where(method => method.IsVoid())
            .Where(method => !method.HasOrInherits<SkipAttribute>());
    }
}