.travis.yml in mutant-0.5.22 vs .travis.yml in mutant-0.5.23

@@ -5,9 +5,12 @@
 rvm:
   - 1.9.3
   - 2.0.0
   - 2.1.2
   - rbx-2
+matrix:
+  allow_failures:
+    - rvm: 2.1.2 # still segfaults on stack overflow on define_method
 notifications:
   irc:
     channels:
       - irc.freenode.org#mutant
     on_success: never