remove ruby 2.2 from CI

Author: ssinghi

.travis.yml

@@ -1,7 +1,6 @@
 language: ruby
 
 rvm:
-  - 2.2
   - 2.3
   - 2.4
   - 2.5
@@ -30,16 +29,10 @@ gemfile:
 matrix:
   fast_finish: true
   exclude:
-    - gemfile: gemfiles/5.2.gemfile
-      rvm: 2.2
-    - gemfile: gemfiles/6.0.gemfile
-      rvm: 2.2
     - gemfile: gemfiles/6.0.gemfile
       rvm: 2.3
     - gemfile: gemfiles/6.0.gemfile
       rvm: 2.4
-    - gemfile: gemfiles/6.1.gemfile
-      rvm: 2.2
     - gemfile: gemfiles/6.1.gemfile
       rvm: 2.3
     - gemfile: gemfiles/6.1.gemfile