Upgrade to mongo-java-driver 2.12.5

Closes gh-2502

Author: wilkinsona

spring-boot-dependencies/pom.xml

@@ -89,7 +89,7 @@
 		<log4j.version>1.2.17</log4j.version>
 		<logback.version>1.1.2</logback.version>
 		<mockito.version>1.9.5</mockito.version>
-		<mongodb.version>2.12.4</mongodb.version>
+		<mongodb.version>2.12.5</mongodb.version>
 		<mysql.version>5.1.34</mysql.version>
 		<reactor.version>1.1.5.RELEASE</reactor.version>
 		<reactor-spring.version>1.1.3.RELEASE</reactor-spring.version>