.travis.yml in sshkit-1.21.1 vs .travis.yml in sshkit-1.21.2

@@ -1,15 +1,18 @@
 language: ruby
 rvm:
+  - 3.0
+  - 2.7
+  - 2.6
   - 2.5
   - 2.4
   - 2.3
   - 2.2
   - 2.1
   - 2.0
 branches:
   only:
-  - master
+    - master
 matrix:
   include:
     # Run Danger only once, on 2.5
     - rvm: 2.5
       script: bundle exec danger