Update version suffix scheme in readme.

Closes #568.

Author: mp911de

README.adoc

@@ -91,7 +91,7 @@ If you'd rather like the latest snapshots of the upcoming major version, use our
 <dependency>
   <groupId>org.springframework.data</groupId>
   <artifactId>spring-data-r2dbc</artifactId>
-  <version>${version}.BUILD-SNAPSHOT</version>
+  <version>${version}-SNAPSHOT</version>
 </dependency>
 
 <repository>