.travis.yml in unread-0.9.1 vs .travis.yml in unread-0.10.0

@@ -1,51 +1,33 @@
 language: ruby
 rvm:
-  - 2.0.0
-  - 2.1.10
-  - 2.2.7
-  - 2.3.3
-  - 2.4.1
+  - 2.2.9
+  - 2.3.6
+  - 2.4.3
+  - 2.5.0
 gemfile:
+  - gemfiles/rails_5_2.gemfile
   - gemfiles/rails_5_1.gemfile
   - gemfiles/rails_5_0.gemfile
   - gemfiles/rails_4_2.gemfile
   - gemfiles/rails_4_1.gemfile
   - gemfiles/rails_4_0.gemfile
-  - gemfiles/rails_3_2.gemfile
-  - gemfiles/rails_3_1.gemfile
-  - gemfiles/rails_3_0.gemfile
 matrix:
   exclude:
-    - rvm: 2.0.0
-      gemfile: gemfiles/rails_5_1.gemfile
-    - rvm: 2.1.10
-      gemfile: gemfiles/rails_5_1.gemfile
-    - rvm: 2.0.0
-      gemfile: gemfiles/rails_5_0.gemfile
-    - rvm: 2.1.10
-      gemfile: gemfiles/rails_5_0.gemfile
-    - rvm: 2.3.3
-      gemfile: gemfiles/rails_3_0.gemfile
-    - rvm: 2.3.3
-      gemfile: gemfiles/rails_3_1.gemfile
-    - rvm: 2.3.3
-      gemfile: gemfiles/rails_3_2.gemfile
-    - rvm: 2.4.1
-      gemfile: gemfiles/rails_3_0.gemfile
-    - rvm: 2.4.1
-      gemfile: gemfiles/rails_3_1.gemfile
-    - rvm: 2.4.1
-      gemfile: gemfiles/rails_3_2.gemfile
-    - rvm: 2.4.1
+    - rvm: 2.4.3
       gemfile: gemfiles/rails_4_0.gemfile
-    - rvm: 2.4.1
+    - rvm: 2.4.3
       gemfile: gemfiles/rails_4_1.gemfile
+    - rvm: 2.5.0
+      gemfile: gemfiles/rails_4_0.gemfile
+    - rvm: 2.5.0
+      gemfile: gemfiles/rails_4_1.gemfile
 before_install: gem update bundler
 sudo: false
 env:
   - DB=sqlite
   - DB=mysql
   - DB=postgres
 before_script:
+  - gem update --system # https://github.com/travis-ci/travis-ci/issues/8978
   - sh -c "if [ '$DB' = 'mysql' ]; then mysql -e 'create database IF NOT EXISTS unread_test;'; fi"
   - sh -c "if [ '$DB' = 'postgres' ]; then psql -c 'create database unread_test;' -U postgres; fi"