.travis.yml in heartcheck-1.6.0 vs .travis.yml in heartcheck-2.0.0

@@ -3,21 +3,11 @@
 install: bundle install -j 4 --retry 3
 script:
   - bin/rspec
 matrix:
   include:
-    - rvm: "1.9.3"
-      gemfile: Gemfile-old-ruby
-    - rvm: "2.0.0"
-      gemfile: Gemfile-old-ruby
-    - rvm: "2.1.0"
-      gemfile: Gemfile-old-ruby
-    - rvm: "2.1.5"
-      gemfile: Gemfile-old-ruby
-    - rvm: "2.2.1"
-      gemfile: Gemfile-old-ruby
-    - rvm: "2.2.2"
     - rvm: "2.3.0"
     - rvm: "2.3.3"
     - rvm: "2.4.1"
     - rvm: "2.5.7"
     - rvm: "2.6.5"
+    - rvm: "2.7.0"