.travis.yml in jbuilder-2.9.1 vs .travis.yml in jbuilder-2.10.0

- old
+ new
@@ -14,37 +14,17 @@
   - 2.6.2
   - ruby-head
   - rbx-3.107
 
 gemfile:
-  - gemfiles/rails_4_2.gemfile
   - gemfiles/rails_5_0.gemfile
   - gemfiles/rails_5_1.gemfile
   - gemfiles/rails_5_2.gemfile
   - gemfiles/rails_6_0.gemfile
   - gemfiles/rails_head.gemfile
 
 matrix:
-  include:
-    - rvm: 1.9
-      gemfile: gemfiles/rails_4_2.gemfile
-    - rvm: 2.0
-      gemfile: gemfiles/rails_4_2.gemfile
-    - rvm: 2.1
-      gemfile: gemfiles/rails_4_2.gemfile
-    - rvm: 2.3
-      gemfile: gemfiles/rails_4_2.gemfile
-    - rvm: jruby-19mode
-      gemfile: gemfiles/rails_4_2.gemfile
-    - rvm: rbx-3.107
-      gemfile: gemfiles/rails_4_2.gemfile
   exclude:
-    - rvm: 2.4.6
-      gemfile: gemfiles/rails_4_2.gemfile
-    - rvm: 2.5.5
-      gemfile: gemfiles/rails_4_2.gemfile
-    - rvm: 2.6.2
-      gemfile: gemfiles/rails_4_2.gemfile
     - rvm: 2.2.10
       gemfile: gemfiles/rails_6_0.gemfile
     - rvm: 2.3.8
       gemfile: gemfiles/rails_6_0.gemfile
     - rvm: 2.4.6