When you have error in unit test util.file.TestUtil, always check that the
directory ./src/test/resources/util/file is in classpath.
You can check that from Project Structure/Modules/Dependencies
Execute test with the generated jar file.
SCALATEST=/Volumes/SD/Dropbox/smcho/bin/jar/scalatest/scalatest_2.11-2.2.6.jar:/Users/smcho/github/ChitchatTypeScala/out/artifacts/chitchattypescala_jar/chitchattypescala.jar
# http://www.scalatest.org/quick_start
scalac -cp $SCALATEST /Users/smcho/github/ChitchatTypeScala/src/test/scala/util/TestBitSetTool.scala
scala -cp $SCALATEST org.scalatest.run util.TestBitSetTool