Docker related things

• Remove Docker majority of bits except for supporting packages, etc.
• Docker will only be installed for Vagrant based clusters via the
  Vagrant provisioner when environment variable NOMAD_DOCKER_ENABLE="true"
  is set
• Update start scripts to be smarter about node role
• Add cgroups packages on Debian/Ubuntu
• Run Nomad as root for now

Variable and config changes

• Renamed vars to be more in line with Nomad terminology
• Switched to merged config style with base, bootstrap, server, client

Revisit Docker support

• Dropping local Docker subsystem support in favor of external role
• Attempting to run nomad as nomad user

Update tasks

• Remove deprecated tasks
• Add conditionals to tasks

Doc meta

v1.1.8

doc meta

Variables, docs, versions updates

• Update default variables
• Update supported versions
• Update documentation — now w/ more header meta (h/t @dochang)

Package and task updates

• Update OS packages
• Update signing key tasks

Keyserver quoting

v1.1.5

keyserver quoting

Quoting and versions

• Update supported versions
• Fix up unarchive task quoting

Package vars

• Fix package name vars