This commit migrates the Nomad package from the 0.10.x line of releases
to 0.11.X.

This allows us to also bump the version of Go that is used to 1.14.x.
NOTE: 1.14.x will be needed for the rest of the 0.11.x releases as Nomad
only bumps patch versions of Go within a release series.

CHANGELOG:

FEATURES:

    Container Storage Interface [beta]: Nomad has expanded support
    of stateful workloads through support for CSI plugins.
    Exec UI: an in-browser terminal for connecting to running allocations.
    Audit Logging (Enterprise): Audit logging support for Nomad
    Enterprise.
    Scaling APIs: new scaling policy API and job scaling APIs to support external autoscalers
    Task Dependencies: introduces lifecycle stanza with prestart and sidecar hooks for tasks within a task group

BACKWARDS INCOMPATIBILITIES:

    driver/rkt: The Rkt driver is no longer packaged with Nomad and is instead
    distributed separately as a driver plugin. Further, the Rkt driver codebase
    is now in a separate
    repository.

IMPROVEMENTS:

    core: Optimized streaming RPCs made between Nomad agents [NixOSGH-7044]
    build: Updated to Go 1.14.1 [NixOSGH-7431]
    consul: Added support for configuring enable_tag_override on service stanzas. [NixOSGH-2057]
    client: Updated consul-template library to v0.24.1 - added support for working with consul connect. Deprecated vault_grace [NixOSGH-7170]
    driver/exec: Added no_pivot_root option for ramdisk use [NixOSGH-7149]
    jobspec: Added task environment interpolation to volume_mount [NixOSGH-7364]
    jobspec: Added support for a per-task restart policy [NixOSGH-7288]
    server: Added minimum quorum check to Autopilot with minQuorum option [NixOSGH-7171]
    connect: Added support for specifying Envoy expose path configurations [NixOSGH-7323] [NixOSGH-7396]
    connect: Added support for using Connect with TLS enabled Consul agents [NixOSGH-7602]

BUG FIXES:

    core: Fixed a bug where group network mode changes were not honored [NixOSGH-7414]
    core: Optimized and fixed few bugs in underlying RPC handling [NixOSGH-7044] [NixOSGH-7045]
    api: Fixed a panic when canonicalizing a jobspec with an incorrect job type [NixOSGH-7207]
    api: Fixed a bug where calling the node GC or GcAlloc endpoints resulted in an error EOF return on successful requests [NixOSGH-5970]
    api: Fixed a bug where /client/allocations/... (e.g. allocation stats) requests may hang in special cases after a leader election [NixOSGH-7370]
    cli: Fixed a bug where nomad agent -dev fails on Windows [NixOSGH-7534]
    cli: Fixed a panic when displaying device plugins without stats [NixOSGH-7231]
    cli: Fixed a bug where alloc exec command in TLS environments may fail [NixOSGH-7274]
    client: Fixed a panic when running in Debian with /etc/debian_version is empty [NixOSGH-7350]
    client: Fixed a bug affecting network detection in environments that mimic the EC2 Metadata API [NixOSGH-7509]
    client: Fixed a bug where a multi-task allocation maybe considered healthy despite a task restarting [NixOSGH-7383]
    consul: Fixed a bug where modified Consul service definitions would not be updated [NixOSGH-6459]
    connect: Fixed a bug where Connect enabled allocation would not stop after promotion [NixOSGH-7540]
    connect: Fixed a bug where restarting a client would prevent Connect enabled allocations from cleaning up properly [NixOSGH-7643]
    driver/docker: Fixed handling of seccomp security_opts option [NixOSGH-7554]
    driver/docker: Fixed a bug causing docker containers to use swap memory unexpectedly [NixOSGH-7550]
    scheduler: Fixed a bug where changes to task group shutdown_delay were not persisted or displayed in plan output [NixOSGH-7618]
    ui: Fixed handling of multi-byte unicode characters in allocation log view [NixOSGH-7470] [NixOSGH-7551]