failed: JAVA_HOME is set to an invalid directory

[patriknw]

https://travis-ci.org/github/akka/akka-grpc-quickstart-scala.g8/jobs/726634401

ERROR: JAVA_HOME is set to an invalid directory: /home/travis/.jabba/jdk/adopt@1.11.0-7
543
544Please set the JAVA_HOME variable in your environment to match the
545location of your Java installation.
546
547The command "sbt new file://$PWD --name=hello-world-grpc --force && pushd hello-world-grpc &&  ./gradlew --console=plain build" exited with 1.

[seglo]

https://travis-ci.org/github/akka/akka-grpc-quickstart-scala.g8/jobs/727144400#L257

[seglo]

https://travis-ci.org/github/akka/akka-grpc-quickstart-scala.g8/jobs/727478095#L257

[ignasi35]

https://travis-ci.org/github/akka/akka-grpc-quickstart-scala.g8/jobs/728626266#L257

That build also failed another jobs with:

~/build/akka/akka-grpc-quickstart-scala.g8/hello-world-grpc ~/build/akka/akka-grpc-quickstart-scala.g8

The JAVA_HOME environment variable is not defined correctly

This environment variable is needed to run this program

NB: JAVA_HOME should point to a JDK not a JRE

See https://travis-ci.org/github/akka/akka-grpc-quickstart-scala.g8/jobs/728626264#L256