Update documentation for create key

[jacobwdv]

The documentation here shows:

    createKeyOptionsModel = new CreateKeyOptions.Builder()
      .bluemixInstance("<instance_id>")
      .createKeyOneOf(inputstream)
      .prefer("return=representation")
      .build();

But I believe it should be:

    createKeyOptionsModel = new CreateKeyOptions.Builder()
      .bluemixInstance("<instance_id>")
      .keyCreateBody(inputstream)
      .prefer("return=representation")
      .build();