Update Ruby versions

Author: dlackty

.travis.yml

@@ -5,11 +5,10 @@ before_install:
   - gem update --system
 
 rvm:
-  - 2.2
-  - 2.3
   - 2.4
   - 2.5
   - 2.6
+  - 2.7
 
 env:
   - RAILS_VERSION=4.2
@@ -19,12 +18,6 @@ env:
 
 matrix:
   exclude:
-    - rvm: 2.2
-      env: RAILS_VERSION=5.0
-    - rvm: 2.2
-      env: RAILS_VERSION=5.1
-    - rvm: 2.2
-      env: RAILS_VERSION=5.2
     - rvm: 2.5
       env: RAILS_VERSION=4.2
     - rvm: 2.5