Bump spring version

pom.xml

@@ -86,7 +86,7 @@
                 <!-- Import dependency management from Spring Boot -->
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-dependencies</artifactId>
-                <version>1.5.16.RELEASE</version>
+                <version>1.5.18.RELEASE</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>