testng version is missing in build.gradle

[kicktipp]

When you import this project with BuildShip into STS it does not succeed and shows an error message because of missing version for testng

diff --git a/server/build.gradle b/server/build.gradle
index d5ac0cc..db8d308 100644
--- a/server/build.gradle
+++ b/server/build.gradle
@@ -64,7 +64,7 @@ dependencies {
   compile("org.codehaus.groovy:groovy-all")
 
   testCompile("org.springframework.boot:spring-boot-starter-test")
-  testCompile("org.testng:testng")
+  testCompile("org.testng:testng:6.10")
 }
 
 compileJava.dependsOn(processResources)