Test against multiple rails versions.

Author: beauby

.travis.yml

@@ -3,10 +3,13 @@ sudo: false
 before_install:
   - bundle update
 rvm:
-  - 2.2.2
-  - 2.3.3
+  - 2.2.7
+  - 2.3.4
   - ruby-head
-
+env:
+  - "RAILS_VERSION=5.1.3"
+  - "RAILS_VERSION=master"
 matrix:
   allow_failures:
     - rvm: ruby-head
+    - env: "RAILS_VERSION=master"

Gemfile

@@ -1,3 +1,16 @@
 source 'https://rubygems.org'
 
+rails_version = ENV['RAILS_VERSION'] || "default"
+rails =
+  case rails_version
+  when 'master'
+    { github: 'rails/rails' }
+  when 'default'
+    '>= 5.0'
+  else
+    "~> #{ENV['RAILS_VERSION']}"
+  end
+
+gem 'rails', rails
+
 gemspec