downgrade jackson-databind to 2.7.9 for java 7 compatibility

Author: d0ze

pom.xml

@@ -44,7 +44,7 @@
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>2.10.0.pr1</version>
+            <version>2.7.9</version>
         </dependency>
 
         <dependency>