.travis.yml in karafka-1.2.5 vs .travis.yml in karafka-1.2.6

@@ -1,13 +1,21 @@
-language: ruby
+dist: trusty
 sudo: false
+language: ruby
+cache: bundler
+
 rvm:
   - 2.3.7
-  - 2.4.3
+  - 2.4.4
   - 2.5.1
   - ruby-head
-  - jruby-head
-script: bundle exec rspec spec/
+  - jruby-9.2.0.0
+
 env:
   global:
     - JRUBY_OPTS='--debug'
-install: bundle install --jobs=3 --retry=3
+
+before_install:
+  - gem install bundler
+  - gem update --system
+
+script: bundle exec rspec