Update DDF version to 2.13.8 (#709)

Update DDF version to 2.13.8

Author: brjeter

pom.xml

@@ -35,7 +35,7 @@
     <properties>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
-        <ddf.version>2.13.7</ddf.version>
+        <ddf.version>2.13.8</ddf.version>
         <ddf.support.version>2.3.9</ddf.support.version>
         <codice-maven.version>0.2</codice-maven.version>
         <codice-test.version>0.3</codice-test.version>