Update jackson-version to 2.8.9

Update jackson from 2.8.7 to 2.8.9 to address FasterXML/jackson-databind#1599

Author: msymons

pom.xml

@@ -497,7 +497,7 @@
         <servlet-api-version>2.5</servlet-api-version>
         <jersey-version>1.13</jersey-version>
         <jersey2-version>2.25.1</jersey2-version>
-        <jackson-version>2.8.7</jackson-version>
+        <jackson-version>2.8.9</jackson-version>
         <logback-version>1.2.3</logback-version>
         <reflections-version>0.9.11</reflections-version>
         <guava-version>20.0</guava-version>