.travis.yml in polish_invoicer-0.0.23 vs .travis.yml in polish_invoicer-0.0.24

@@ -1,6 +1,5 @@
 language: ruby
 rvm:
-  - 2.2.10
-  - 2.3.7
-  - 2.4.4
-  - 2.5.1
+  - 2.5.8
+  - 2.6.6
+  - 2.7.2