Disable the flaky ruby spec example on master

See opal#1544 (comment)

Author: elia

spec/filters/bugs/module.rb

@@ -82,6 +82,7 @@
   fails "Module#include detects cyclic includes"
   fails "Module#include does not override existing constants in modules and classes"
   fails "Module#include doesn't include module if it is included in a super class"
+  fails "Module#include recursively includes new mixins"
   fails "Module#include? raises a TypeError when no module was given"
   fails "Module#include? returns true if the given module is included by self or one of it's ancestors"
   fails "Module#instance_method gives UnboundMethod method name, Module defined in and Module extracted from"