add 0.6 testing explicitly

tlnagy · tlnagy · commit 1bfbd515dee7 · 2017-04-06T14:46:29.000-07:00
nightly will likely stop pointing at 0.6 here soon
diff --git a/.travis.yml b/.travis.yml
@@ -4,6 +4,7 @@ os:
   - osx
 julia:
   - 0.5
+  - 0.6
   - nightly
 notifications:
   email: false
