Update spark dependency version to 3.0.2.

Author: heuermh

pom.xml

@@ -73,7 +73,7 @@
     <scala.version>2.12.8</scala.version>
     <scala.version.prefix>2.12</scala.version.prefix>
     <slf4j.version>1.7.30</slf4j.version>
-    <spark.version>3.0.1</spark.version>
+    <spark.version>3.0.2</spark.version>
   </properties>
   <build>
     <pluginManagement>