run scalikejdbcGenAllForce before compile

scalikejdbc_build.sbt

lazy val removeTestTask = TaskKey[Unit]("removeTest", "Deletes scalikeJDBC test file")
removeTestTask := {
  println("remove test files.")
  sbt.IO.delete(new File("src/test/scala/path/to/generated/code"))
}
compile in Compile <<= (compile in Compile).dependsOn(removeTestTask)

scalikejdbcSettings
compile in Compile <<= (compile in Compile).dependsOn(scalikejdbc.mapper.SbtKeys.scalikejdbcGenAllForce.in(Compile).toTask(""))