.travis.yml in lightio-0.1.1 vs .travis.yml in lightio-0.2.0

@@ -8,9 +8,10 @@
   - ruby-head
 
 env:
   global:
     - JRUBY_OPTS="--dev -J-Djruby.launch.inproc=true -J-Xmx1024M"
+    - COVERAGE=true
 
 matrix:
   allow_failures:
     - rvm: ruby-head
     - rvm: jruby-9.1.15.0