.travis.yml in audited-4.3.0 vs .travis.yml in audited-4.4.0

@@ -2,25 +2,35 @@
 cache: bundler
 rvm:
   - 2.1
   - 2.2.4
   - 2.3.1
+  - 2.4.1
   - ruby-head
 env:
   - DB=SQLITE
   - DB=POSTGRES
   - DB=MYSQL
+addons:
+  postgresql: "9.4"
 gemfile:
   - gemfiles/rails40.gemfile
   - gemfiles/rails41.gemfile
   - gemfiles/rails42.gemfile
   - gemfiles/rails50.gemfile
+  - gemfiles/rails51.gemfile
 matrix:
   allow_failures:
     - rvm: ruby-head
   exclude:
     - rvm: 2.1
       gemfile: gemfiles/rails50.gemfile
+    - rvm: 2.1
+      gemfile: gemfiles/rails51.gemfile
+    - rvm: 2.4.1
+      gemfile: gemfiles/rails40.gemfile
+    - rvm: 2.4.1
+      gemfile: gemfiles/rails41.gemfile
   fast_finish: true
 branches:
   only:
   - master
 sudo: false