.travis.yml in async-io-1.27.1 vs .travis.yml in async-io-1.27.2

@@ -6,9 +6,10 @@
   include:
     - rvm: 2.3
     - rvm: 2.4
     - rvm: 2.5
     - rvm: 2.6
+    - rvm: 2.7
     - rvm: 2.6
       env: COVERAGE=PartialSummary,Coveralls
     - rvm: truffleruby
     - rvm: jruby-head
       env: JRUBY_OPTS="--debug -X+O"