add two tests to ensure {Lasso, Ridge}.setIntercept will throw an exceptions

Author: mengxr

mllib/src/test/scala/org/apache/spark/mllib/regression/LassoSuite.scala

@@ -17,11 +17,8 @@
 
 package org.apache.spark.mllib.regression
 
-
-import org.scalatest.BeforeAndAfterAll
 import org.scalatest.FunSuite
 
-import org.apache.spark.SparkContext
 import org.apache.spark.mllib.util.{LinearDataGenerator, LocalSparkContext}
 
 class LassoSuite extends FunSuite with LocalSparkContext {
@@ -104,4 +101,10 @@ class LassoSuite extends FunSuite with LocalSparkContext {
     // Test prediction on Array.
     validatePrediction(validationData.map(row => model.predict(row.features)), validationData)
   }
+
+  test("do not support intercept") {
+    intercept[UnsupportedOperationException] {
+      new LassoWithSGD().setIntercept(true)
+    }
+  }
 }

mllib/src/test/scala/org/apache/spark/mllib/regression/RidgeRegressionSuite.scala

@@ -17,14 +17,11 @@
 
 package org.apache.spark.mllib.regression
 
-
 import org.jblas.DoubleMatrix
-import org.scalatest.BeforeAndAfterAll
 import org.scalatest.FunSuite
 
 import org.apache.spark.mllib.util.{LinearDataGenerator, LocalSparkContext}
 
-
 class RidgeRegressionSuite extends FunSuite with LocalSparkContext {
 
   def predictionError(predictions: Seq[Double], input: Seq[LabeledPoint]) = {
@@ -74,4 +71,10 @@ class RidgeRegressionSuite extends FunSuite with LocalSparkContext {
     assert(ridgeErr < linearErr,
       "ridgeError (" + ridgeErr + ") was not less than linearError(" + linearErr + ")")
   }
+
+  test("do not support intercept") {
+    intercept[UnsupportedOperationException] {
+      new RidgeRegressionWithSGD().setIntercept(true)
+    }
+  }
 }