Java projects are forced to include ScalaTest as dependency

[jlprat]

Currently if you want to use the Java test suit in a Java project you need to include ScalaTest as a dependency.

Java developers don't need this dependency on their projects, thus it should not be forced to be added.

Currently if it's not added you get the following error:

[info] [info] Compiling 3 Java sources to /tmp/sbt_823bc44b/scripted/target/scala-2.12/test-classes...
[info] [error] /tmp/sbt_823bc44b/scripted/src/test/java/com/example/HttpServerHttpAppTest.java:10: cannot access org.scalatest.junit.JUnitSuiteLike
[info] [error]   class file for org.scalatest.junit.JUnitSuiteLike not found
[info] [error] public class HttpServerHttpAppTest extends JUnitRouteTest {
[info] [error] /tmp/sbt_823bc44b/scripted/src/test/java/com/example/HttpServerHttpAppTest.java:17: cannot find symbol
[info] [error]   symbol:   method testRoute(akka.http.javadsl.server.Route)
[info] [error]   location: class com.example.HttpServerHttpAppTest
[info] [error]     appRoute = testRoute(server.route());
[info] [error] (test:compileIncremental) javac returned nonzero exit code

Discovered during akka/akka-http-java-seed.g8#1

[jrudolph]

Yep, good one. Probably there's no reason that JUnitSuiteLike is referenced at all.