Cleanup Travis file

Author: n-rodriguez

.travis.yml

@@ -1,44 +1,55 @@
+---
+os: linux
+dist: bionic
+
 language: ruby
 cache: bundler
-sudo: required
 rvm:
   - 2.7.1
   - 2.6.6
   - 2.5.8
   - 2.4.10
   - ruby-head
+
 gemfile:
   - gemfiles/rails_5.0.7.gemfile
   - gemfiles/rails_5.1.7.gemfile
   - gemfiles/rails_5.2.3.gemfile
   - gemfiles/rails_6.0.1.gemfile
+
 services:
   - postgresql
   - mysql
+
 addons:
   postgresql: '9.6'
+
 before_install:
   - sh -c "if [ '$DB_ADAPTER' = 'mysql2' ]; then mysql -e 'create database ajax_datatables_rails;'; fi"
   - sh -c "if [ '$DB_ADAPTER' = 'postgresql' ]; then psql -c 'create database ajax_datatables_rails;' -U postgres; fi"
   - sh -c "if [ '$DB_ADAPTER' = 'oracle_enhanced' ]; then ./spec/install_oracle.sh; fi"
+
 env:
   global:
     - ORACLE_COOKIE=sqldev
     - ORACLE_FILE=oracle11g/xe/oracle-xe-11.2.0-1.0.x86_64.rpm.zip
     - ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe
     - ORACLE_SID=XE
-  matrix:
+  jobs:
     - DB_ADAPTER=postgresql
     - DB_ADAPTER=mysql2
     - DB_ADAPTER=sqlite3
     - DB_ADAPTER=oracle_enhanced
-matrix:
+
+jobs:
   exclude:
     - rvm: 2.4.10
       gemfile: gemfiles/rails_6.0.1.gemfile
+
 before_script:
   - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
   - chmod +x ./cc-test-reporter
   - ./cc-test-reporter before-build
+
 after_script:
   - ./cc-test-reporter after-build --exit-code $TRAVIS_TEST_RESULT