Allow failure on osx due to current bug in nightly

dlfivefifty · dlfivefifty · commit c2ce26f64521 · 2018-06-20T11:47:28.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -6,6 +6,9 @@ os:
 julia:
   - 0.6
   - nightly
+matrix:
+  allow_failures:
+    - os: osx
 notifications:
   email: false
 after_success:
