Broaden the net to see whether it is only perl 5.26 on the travis docker image...

Broaden the net to see whether it is only perl 5.26 on the travis docker image which is failing gene.t

.travis.yml

@@ -2,6 +2,8 @@ language: perl
 
 perl:
   - '5.14'
+  - '5.16'
+  - '5.24'
   - '5.26'
 
 env: