allow jruby to fail on Travis because reasons
allow jruby to fail on Travis because reasons

Just to mention a few:
  - using guard with JRuby is so slow, so I doubt anyone is using it
  - Kernel.system doesn't support options (and no one seemed to care)
  - rdiscount doesn't install for JRuby
  - Cucumber + Aruba + Pry + threads + popen3 together make JRuby
  unusable for anything serious
  - tests pass reliably except spawned cucumber features on JRuby

garettarrowood/guard,sideci-sample/sideci-sample-guard,sdgdsffdsfff/guard,guard/guard,100star/guard,baberthal/guard,ginkel/guard,pjump/guard