Fixed Jackson related security issue

Change-Id: I2053c14837683e419be705814631a3ffaad8a486
diff --git a/pom.xml b/pom.xml
index 4661e94..a78439e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
 
 	<groupId>de.ids_mannheim.korap</groupId>
 	<artifactId>Koral</artifactId>
-	<version>0.30</version>
+	<version>0.31</version>
 	<packaging>jar</packaging>
 	<name>Koral</name>
 	<url>http://maven.apache.org</url>
@@ -36,7 +36,7 @@
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>		
-		<jackson.version>2.9.1</jackson.version>
+		<jackson.version>[2.9.5,)</jackson.version>
 		<java.version>1.8</java.version>
 	</properties>