add 'oraclejdk10' to Travis build matrix

[sullis]

Description

add 'oraclejdk10' to Travis build matrix

Motivation and Context

add 'oraclejdk10' to Travis build matrix

Testing

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• I have read the CONTRIBUTING document
• Local run of mvn install succeeds
• My code follows the code style of this project
• My change requires a change to the Javadoc documentation
• I have updated the Javadoc documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed
• A short description of the change has been added to the CHANGELOG

License

• I confirm that this pull request can be released under the Apache 2 license

[sullis]

Travis CI build failed.

"java.lang.NoClassDefFoundError: javax/annotation/Generated"

[sullis]

similar issue: google/auto#560

[sullis]

similar issue: google/dagger#880

[sullis]

explanation about the 'Generated' annotation:
https://blog.codefx.org/java/jsr-305-java-9/

[sullis]

Oops. ' javax.annotation.processing.Generated' was introduced in JDK 9. It doesn't exist in JDK 8.

[zoewangg]

Thanks for the PR. Instead of adding extra loads on Travis, we have created Codebuild jobs to build with JDK9 and JDK10.

Side note, we fixed the NoClassDefFoundError issue by avoiding using javax.annotation.Generated and using our own @Generated annotation instead. See also #584