Latest stable release of Zoe 2017.12

We just released version 2017.12 of Zoe, the most notable changes are:

• New Docker Engine back-end, the Swarm back-end is now deprecated
• Nodes and ZApps can be labelled for constraining execution placement, for example to run ZApps only on nodes with GPUs
• Use non-reserved memory, cores, labels and image availability to take placement decisions
• The elastic scheduler is considered stable, the simple scheduler is now deprecated
• Zoe logs are more audit-friendly
• Distinguish between reserved, allocated and in-use resources
• Allocate cores automatically, respecting the minimum configured in the ZApp
• Allow for more options and resource limits to be customized on the web interface (users or admins, not for guests), maximum limits are set in the zoe.conf file
• Additional volumes can be mounted by specifying them in the zoe.conf file
• Elastic services that die are rescheduled on a new node
• Optional support for gathering usage metrics via KairosDB, for now these metrics are only used in the status page plots
• More configuration options for LDAP authentication