Upgrade to Mongodb 3.4.2

Closes gh-8373

spring-boot-dependencies/pom.xml

@@ -133,7 +133,7 @@
 		<mariadb.version>1.5.8</mariadb.version>
 		<mssql-jdbc.version>6.1.0.jre7</mssql-jdbc.version>
 		<mockito.version>1.10.19</mockito.version>
-		<mongodb.version>3.4.1</mongodb.version>
+		<mongodb.version>3.4.2</mongodb.version>
 		<mysql.version>5.1.40</mysql.version>
 		<narayana.version>5.5.2.Final</narayana.version>
 		<nekohtml.version>1.9.22</nekohtml.version>