Netty 4.1.13 -> 4.1.17

Author: Sean Sullivan

pom.xml

@@ -92,7 +92,7 @@
         <assertj.version>3.8.0</assertj.version>
         <equalsverifier.version>2.3.3</equalsverifier.version>
         <guava.version>19.0</guava.version>
-        <netty.version>4.1.13.Final</netty.version>
+        <netty.version>4.1.17.Final</netty.version>
         <unitils.version>3.3</unitils.version>
         <xmlunit.version>1.3</xmlunit.version>
         <jacksonjr.version>2.9.1</jacksonjr.version>