Merge pull request #51 from khiav223577/feature/support_ruby_27

Support Ruby 2.7

.travis.yml

@@ -6,6 +6,7 @@ language: ruby
 rvm:
   - 2.2
   - 2.6
+  - 2.7
 gemfile:
   - gemfiles/3.2.gemfile
   - gemfiles/4.2.gemfile
@@ -17,11 +18,17 @@ matrix:
   exclude:
     - gemfile: gemfiles/3.2.gemfile
       rvm: 2.6
+    - gemfile: gemfiles/3.2.gemfile
+      rvm: 2.7
+    - gemfile: gemfiles/4.2.gemfile
+      rvm: 2.7
     - gemfile: gemfiles/6.0.gemfile
       rvm: 2.2
 before_install:
-  - gem i rubygems-update -v '<3' && update_rubygems
-  - gem install bundler -v 1.17.3
+  - if [`ruby -e 'exit(RUBY_VERSION.to_f < 2.7)'`]; then
+      gem i rubygems-update -v '< 3' && update_rubygems;
+      gem install bundler -v '< 2';
+    fi
   - gem --version
   - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
   - chmod +x ./cc-test-reporter