.travis.yml in pinch_hitter-0.6.0 vs .travis.yml in pinch_hitter-0.7.0

@@ -1,7 +1,11 @@
 language: ruby
 rvm:
-  - 2.1.9
-  - 2.2.5
-  - 2.3.1
+  - 2.1.10
+  - 2.2.10
+  - 2.3.8
+  - 2.4.9
+  - 2.5.7
+  - 2.6.5
+  - 2.7.0
 before_install:
   - gem update bundler