.travis.yml in enum_kit-0.1.0 vs .travis.yml in enum_kit-0.2.1

@@ -1,13 +1,23 @@
 language: ruby
 rvm:
   - 2.6.5
+gemfile:
+  - travis/gemfiles/5.2.gemfile
+  - travis/gemfiles/6.0.gemfile
 services:
   - postgresql
 before_install:
   - gem update --system
   - gem install bundler
 before_script:
   - psql -c 'CREATE DATABASE enum_kit_test;' -U postgres
+addons:
+  postgresql: 10
+  apt:
+    packages:
+      - postgresql-10
+      - postgresql-client-10
 env:
   global:
     - DATABASE_URL="postgresql://127.0.0.1:5432/enum_kit_test"
+    - RSPEC_DEFAULT_FORMATTER=doc