.travis.yml in mpd_client-0.1.0 vs .travis.yml in mpd_client-0.2.0

@@ -1,6 +1,12 @@
 language: ruby
+
+rvm:
+  - 3.1.2
+  - 3.0.4
+  - 2.7.6
+
 script:
   - rspec
   - rubocop