Update application.properties

Author: DFanso

src/main/resources/application.properties

@@ -1,5 +1,5 @@
 spring.application.name=spring-jwt-auth
-spring.datasource.url=
+spring.datasource.url=${SPRING_DATASOURCE_URL}
 spring.datasource.username=dfanso
 spring.datasource.password=48W7m7POnVrHOBtzXFUdr9cm02C0JfzR
 spring.datasource.driver-class-name=org.postgresql.Driver