Bump spring-security-oauth2 in /authentication-server (#44)

diff --git a/authentication-server/pom.xml b/authentication-server/pom.xml
index 698227f..3ae4d9f 100644
--- a/authentication-server/pom.xml
+++ b/authentication-server/pom.xml
@@ -58,7 +58,7 @@
       <dependency>
         <groupId>org.springframework.security.oauth</groupId>
         <artifactId>spring-security-oauth2</artifactId>
-        <version>2.3.2.RELEASE</version>
+        <version>2.3.6.RELEASE</version>
       </dependency>
       <dependency>
         <groupId>org.springframework.security</groupId>