Provide toString method for ScriptCompilationConfigurationWrapper

This is needed for debug and logging proposes

libraries/scripting/common/src/kotlin/script/experimental/api/scriptCompilation.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -44,6 +44,10 @@ open class ScriptCompilationConfiguration(baseConfigurations: Iterable<ScriptCom
         return if (newConfiguration == this) this
         else newConfiguration
     }
+
+    override fun toString(): String {
+        return "ScriptCompilationConfiguration($providedProperties)"
+    }
 }
 
 /**