Adding unreleased 5.6.4 version number to Version.java
Adding unreleased 5.6.4 version number to Version.java

strapdata/elassandra,vroyer/elassandra,strapdata/elassandra,strapdata/elassandra,vroyer/elassandra,strapdata/elassandra,vroyer/elasticassandra,vroyer/elasticassandra,vroyer/elasticassandra,strapdata/elassandra,vroyer/elassandra