Use trusty image

cheton · cheton · commit 44c672eed578 · 2016-06-20T10:26:58.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,3 +1,4 @@
+dist: trusty
 language: node_js
 node_js:
   - '5'
@@ -7,4 +8,3 @@ node_js:
   - 'iojs'
 after_success:
   - npm run coveralls
-  - npm run coverage-clean
