Upgrade to freemarker 2.3.29

Fixes gh-65

Author: kazuki43zoo

pom.xml

@@ -88,7 +88,7 @@
     <dependency>
       <groupId>org.freemarker</groupId>
       <artifactId>freemarker</artifactId>
-      <version>2.3.28</version>
+      <version>2.3.29</version>
     </dependency>
     <dependency>
       <groupId>org.apache.commons</groupId>