Bump version to 6
Bump version to 6

Version 5 was just released.

Signed-off-by: Tomas Sedovic <2bc6038c3dfca09b2da23c8b6da8ba884dc2dcc2@sedovic.cz>

sdake/heat-jeos,openstack/heat-cfntools,steveb/heat-cfntools,bbandaru/heat-cfntools,steveb/heat-cfntools