Adding attribution info for the Iris dataset (#2234)

* Adding attribution info for the Iris dataset

* nit

Author: najeeb-kazmi

test/data/README.md

@@ -28,6 +28,16 @@ The datasets are provided under the original terms that Microsoft received such
 >
 >https://archive.ics.uci.edu/ml/datasets/Adult
 
+### UCI Iris Flower Dataset
+
+>Redistributing the datasets "iris.data" and "iris.txt" with attribution:
+>
+>Dua, D. and Karra Taniskidou, E. (2017). UCI Machine Learning Repository [https://archive.ics.uci.edu/ml]. Irvine, CA: University of California, School of Information and Computer Science.
+>
+>With modifications to "iris.txt" by changing the separator character, order of columns, and numerical encoding of labels.
+>
+>https://archive.ics.uci.edu/ml/datasets/iris
+
 ### Breast Cancer Wisconsin
 
 Redistributing the dataset "breast-cancer.txt" with attribution: