Updating version to reflect development work for 2.6.0
Updating version to reflect development work for 2.6.0

datastax/cpp-driver,mikefero/cpp-driver,mikefero/cpp-driver,hpcc-systems/cpp-driver,datastax/cpp-driver,hpcc-systems/cpp-driver,datastax/cpp-driver,datastax/cpp-driver,mikefero/cpp-driver,mikefero/cpp-driver,mikefero/cpp-driver,hpcc-systems/cpp-driver,hpcc-systems/cpp-driver