Update travis ci config

.travis.yml

@@ -1,30 +1,22 @@
 language: ruby
 rvm:
-  - 1.9.3
-  - 2.0
-  - 2.1
-  - 2.2
-  - jruby
+  - 2.4
 
 env:
   global:
     - "JRUBY_OPTS=-Xcext.enabled=true"
   matrix:
-    - DB=sqlite
     - DB=mysql
-    - DB=postgresql
 
 script:
   - RAILS_ENV=test bundle exec rake db:migrate --trace
   - TRAVIS=true bundle exec rspec spec/
 
 gemfile:
-  - gemfiles/Gemfile.rails-4.1.x
   - gemfiles/Gemfile.rails-4.2.x
   - Gemfile
 
 before_script:
   - mysql -e 'create database recruiter_test'
-  - psql -c 'create database recruiter_test' -U postgres
 
 sudo: false