compilation error: package org.bitcoinj.testing does not exist

This exception occurs while compiling lighthouse. 
Bitcoinj recently "Moved org.bitcoinj.testing package to test classpath."
The [testing folder](https://github.com/bitcoinj/bitcoinj/tree/v0.13.4/core/src/main/java/org/bitcoinj/testing) is deleted from bitcoinj [master branch ](https://github.com/bitcoinj/bitcoinj/tree/master/core/src/main/java/org/bitcoinj)
