Prepare next development iteration.

Set Spring Session version to 2.6.4-SNAPSHOT.

Set version to 2.6.3-SNAPSHOT.

Author: jxblum

gradle.properties

@@ -8,6 +8,6 @@ springDataBomVersion=2021.1.7
 springDataCommonsVersion=2.6.7
 springDataGeodeVersion=2.6.7
 springDataGeodeTestVersion=0.2.3-Q
-springSessionVersion=2.6.3
+springSessionVersion=2.6.4-SNAPSHOT
 springSessionBomVersion=2021.1.3
-version=2.6.2
+version=2.6.3-SNAPSHOT