Add more specific Gemfile for Rails versions

Author: olleolleolle

.travis.yml

@@ -1,24 +1,32 @@
 language: ruby
 cache: bundler
-# To use rbx environment.
 dist: trusty
 rvm:
   - 2.2
   - 2.3
   - 2.4
   - 2.5
   - 2.6
+  - 2.7
   - ruby-head
   - jruby-9.2.6.0
 matrix:
   include:
     - gemfile: Gemfile
-      rvm: 2.5
-    - gemfile: Gemfile
-      rvm: 2.6
+      rvm: 2.7
     - gemfile: Gemfile
       rvm: ruby-head
-    - gemfile: Gemfile
+    - gemfile: gemfiles/Gemfile-6-1-stable
+      rvm: 2.7
+    - gemfile: gemfiles/Gemfile-6-1-stable
+      rvm: 2.6
+    - gemfile: gemfiles/Gemfile-6-1-stable
+      rvm: 2.5
+    - gemfile: gemfiles/Gemfile-6-0-stable
+      rvm: 2.6
+    - gemfile: gemfiles/Gemfile-6-0-stable
+      rvm: 2.5
+    - gemfile: gemfiles/Gemfile-6-0-stable
       rvm: jruby-9.2.6.0
     - gemfile: gemfiles/Gemfile-5-2-stable
       rvm: 2.2

gemfiles/Gemfile-6-0-stable

@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+gemspec path: '..'
+
+gem 'rails', git: 'https://github.com/rails/rails', ref: '6-0-stable'
+

gemfiles/Gemfile-6-1-stable

@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+gemspec path: '..'
+
+gem 'rails', git: 'https://github.com/rails/rails', ref: '6-1-stable'
+