.travis.yml in fresh_connection-2.3.2 vs .travis.yml in fresh_connection-2.4.0.rc1

@@ -10,18 +10,15 @@
   - psql -c 'create database fresh_connection_test_master;' -U postgres
   - psql -c 'create database fresh_connection_test_replica1;' -U postgres
   - psql -c 'create database fresh_connection_test_replica2;' -U postgres
 cache: bundler
 rvm:
-  - 2.1.10
-  - 2.2.6
-  - 2.3.3
-  - 2.4.0
+  - 2.2.7
+  - 2.3.4
+  - 2.4.1
 gemfile:
   - gemfiles/rails42.gemfile
   - gemfiles/rails50.gemfile
+  - gemfiles/rails51.gemfile
 matrix:
-  exclude:
-    - rvm: 2.1.10
-      gemfile: gemfiles/rails50.gemfile
   fast_finish: true
 bundler_args: --jobs 3 --retry 3