Removing java 6 build since source input is Java 7

4 jobs for master in 44 minutes and 3 seconds (queued for 24 seconds)
Status Job ID Name Coverage
  Build
passed #8284
jars-j8

00:00:35

passed #8283
java8

00:16:08

 
  Test
passed #8286
allowed to fail
java11

00:13:49

passed #8285
java7

00:13:30