bindingsEngine.containsKey throws Exception when key is not found #11

If no variable called ten is defined, the following Scala code throws java.lang.NullPointerException:

new ScriptEngineManager()
  .getEngineByName("Java")
  .getContext
  .getBindings(ScriptContext.ENGINE_SCOPE)
  .containsKey("ten")

Similar code works for scripting-scala. However, this bug can is also present for scripting-clojure.