.travis.yml in biodiversity-3.5.1 vs .travis.yml in biodiversity-4.0.0

@@ -1,11 +1,6 @@
 rvm:
-  - 2.1
-  - 2.2
-  - 2.3
-  - 2.4
   - 2.5
+  - 2.6
 branches:
   only:
       - master
-before_script:
-  - bundle exec rake tt