Upgrade to commons-parent 18.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1066161 13f79535-47bb-0310-9956-ffa450edef68

Author: garydgregory

pom.xml

@@ -22,7 +22,7 @@
   <parent>
     <groupId>org.apache.commons</groupId>
     <artifactId>commons-parent</artifactId>
-    <version>17</version>
+    <version>18</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <groupId>commons-codec</groupId>