switch to next snapshot version until released versions are available in maven central

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1767395 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index af56dad..ae2473b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -51,7 +51,7 @@
         <dependency>
             <groupId>org.apache.sling</groupId>
             <artifactId>org.apache.sling.models.api</artifactId>
-            <version>1.3.0</version>
+            <version>1.3.1-SNAPSHOT</version>
             <scope>provided</scope>
         </dependency>
         <dependency>