Added Security Layer for Admin Controller

src/main/java/com/school/project/security/OAuth2ServerConfiguration.java

@@ -50,7 +50,7 @@ public class OAuth2ServerConfiguration {
                     .authorizeRequests()
                     .antMatchers("/register/**").permitAll()
                     .antMatchers("/student/**").hasAuthority("STUDENT")
-                    .antMatchers("/department/**", "/course/**").hasAuthority("ADMIN");
+                    .antMatchers("/department/**", "/course/**","/admin/**").hasAuthority("ADMIN");
         }
     }