Merge pull request #156 from powsybl/bump-to-version-2.31.0

Bump to version 2.31.0

Author: carojeandat

pom.xml

@@ -19,7 +19,7 @@
 
     <artifactId>powsybl-case-server</artifactId>
     <name>Case server</name>
-    <version>2.31.0-SNAPSHOT</version>
+    <version>2.31.0</version>
 
     <licenses>
         <license>