Configure travis.yml

.travis.yml

@@ -1,6 +1,7 @@
----
 language: ruby
-cache: bundler
+rvm: 2.7
-rvm:
+script: bundle exec rake test
-  - 2.7.1
+notifications:
-before_install: gem install bundler -v 2.1.4
+  email:
+    on_success: never
+    on_failure: change