Update build matrix

- Add Rails 6.1
- Add Ruby 3.0
- Change Edge Rails branch name

.travis.yml

@@ -8,26 +8,42 @@ rvm:
   - '2.5'
   - '2.6'
   - '2.7'
+  - '3.0'
   - ruby-head
 gemfile:
-  - gemfiles/rails_5.2.gemfile
+  - gemfiles/rails_5_2.gemfile
   - gemfiles/rails_6_0.gemfile
+  - gemfiles/rails_6_1.gemfile
   - gemfiles/rails_edge.gemfile
 matrix:
   fast_finish: true
   exclude:
+    - rvm: '3.0'
+      gemfile: gemfiles/rails_5_2.gemfile
+    - rvm: 'ruby-head'
+      gemfile: gemfiles/rails_5_2.gemfile
     - rvm: '2.2'
       gemfile: gemfiles/rails_6_0.gemfile
     - rvm: '2.3'
       gemfile: gemfiles/rails_6_0.gemfile
     - rvm: '2.4'
       gemfile: gemfiles/rails_6_0.gemfile
+    - rvm: '2.2'
+      gemfile: gemfiles/rails_6_1.gemfile
+    - rvm: '2.3'
+      gemfile: gemfiles/rails_6_1.gemfile
+    - rvm: '2.4'
+      gemfile: gemfiles/rails_6_1.gemfile
     - rvm: '2.2'
       gemfile: gemfiles/rails_edge.gemfile
     - rvm: '2.3'
       gemfile: gemfiles/rails_edge.gemfile
     - rvm: '2.4'
       gemfile: gemfiles/rails_edge.gemfile
+    - rvm: '2.5'
+      gemfile: gemfiles/rails_edge.gemfile
+    - rvm: '2.6'
+      gemfile: gemfiles/rails_edge.gemfile
   allow_failures:
     - rvm: ruby-head
     - gemfile: gemfiles/rails_edge.gemfile

gemfiles/rails_6_1.gemfile

@@ -0,0 +1,7 @@
+source "https://rubygems.org"
+
+gem "actionpack", github: "rails/rails", branch: "6-1-stable"
+gem "activerecord", github: "rails/rails", branch: "6-1-stable"
+gem "railties", github: "rails/rails", branch: "6-1-stable"
+
+gemspec :path => "../"

gemfiles/rails_edge.gemfile

@@ -1,12 +1,11 @@
 source "https://rubygems.org"
 
-git "https://github.com/rails/rails.git", :branch => "master" do
+git "https://github.com/rails/rails.git", :branch => "main" do
   gem "actionpack"
   gem "activerecord"
   gem "railties"
 end
 
 gem "rack", :git => "https://github.com/rack/rack.git", :branch => "master"
-gem "arel", :git => "https://github.com/rails/arel.git", :branch => "master"
 
 gemspec :path => "../"