code does not compile on jdk11 with `package javax.xml.bind does not exist`

[simon]

If we try to build with JDK11:

$java --version
openjdk 11.0.3 2019-04-16
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.3+7)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.3+7, mixed mode)

Then we get a compile error from trying to use javax.bind:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.2:compile (default-compile) on project srp6a: Compilation failure
[ERROR] /Users/Shared/nimbus-srp/src/main/java/com/nimbusds/srp6/cli/SRP6Tool.java:[198,78] package javax.xml.bind does not exist

‌