Update example version to 2.9.7 (FasterXML#2161)

Since a security issue is being fixed on the latest patch I think it makes sense to make this change, being that some people skip checking the badges and go straight to this section 👍

Author: lbalmaceda

README.md

@@ -25,7 +25,7 @@ Functionality of this package is contained in Java package `com.fasterxml.jackso
 <properties>
   ...
   <!-- Use the latest version whenever possible. -->
-  <jackson.version>2.9.5</jackson.version>
+  <jackson.version>2.9.7</jackson.version>
   ...
 </properties>