[SPARK-2199][mllib] colt dependency removed

Author: akopich

mllib/pom.xml

@@ -112,11 +112,6 @@
       <type>test-jar</type>
       <scope>test</scope>
     </dependency>
-    <dependency>
-        <groupId>colt</groupId>
-        <artifactId>colt</artifactId>
-        <version>1.2.0</version>
-    </dependency>
   </dependencies>
   <profiles>
     <profile>

mllib/src/main/scala/org/apache/spark/mllib/stat/impl/DirichletDistribution.scala

@@ -19,7 +19,7 @@
 
 package org.apache.spark.mllib.stat.impl
 
-import cern.jet.stat.Gamma
+import org.apache.commons.math3.special.Gamma
 
 private[mllib] class DirichletDistribution(private[mllib] val alpha: Float) extends Serializable {
   private def logBeta(x: Array[Float]) = {