Drop openjdk12 and openjdk13 since these are neither LTS or the latest.

garydgregory · garydgregory · commit 5baac5c252bd · 2020-08-10T12:15:17.000-04:00
diff --git a/.travis.yml b/.travis.yml
@@ -18,8 +18,6 @@ language: java
 jdk:
   - openjdk8
   - openjdk11
-  - openjdk12
-  - openjdk13
   - openjdk14  
   - openjdk-ea
 
