JDK 9 support (Replace the use of JAXB)

[eugene yokota]

steps

Try running sbt 1 on JDK 9.

problem

[error] (*:update) java.lang.NoClassDefFoundError: javax/xml/bind/DatatypeConverter

notes

#11 introduces dependency to JAXB, which is not part of the classpath on JDK 9. Figure out an alternative or add dependency to it.

[eugene yokota]

Fixed by #54