Polishing.

Fix snapshot repository URL.

See #3097

Author: mp911de

README.adoc

@@ -42,9 +42,9 @@ If you'd rather like the latest snapshots of the upcoming major version, use our
 </dependency>
 
 <repository>
-  <id>spring-libs-snapshot</id>
+  <id>spring-snapshot</id>
   <name>Spring Snapshot Repository</name>
-  <url>https://repo.spring.io/libs-snapshot</url>
+  <url>https://repo.spring.io/snapshot</url>
 </repository>
 ----