Update sysutils/consul to 0.8.0

BREAKING CHANGES:

- Command-Line Interface RPC Deprecation: The RPC client interface has
  been removed.
- Version 8 ACLs Are Now Opt-Out: The acl_enforce_version_8
  configuration now defaults to true to enable full version 8 ACL
  support by default.
- Remote Exec Is Now Opt-In: The default for disable_remote_exec was
  changed to "true", so now operators need to opt-in to having agents
  support running commands remotely via consul exec.
- Raft Protocol Compatibility: When upgrading to Consul 0.8.0 from a
  version lower than 0.7.0, users will need to set the -raft-protocol
  option to 1 in order to maintain backwards compatibility with the old
  servers during the upgrade.

FEATURES:

- Autopilot: A set of features has been added to allow for automatic
  operator-friendly management of Consul servers.
- Dead Server Cleanup: Dead servers will periodically be cleaned up and
  removed from the Raft peer set
- Server Health Checking: An internal health check has been added to
  track the stability of servers.
- New Server Stabilization: When a new server is added to the cluster,
  there will be a waiting period where it must be healthy and stable for
  a certain amount of time before being promoted to a full, voting member.
- Advanced Redundancy: (Consul Enterprise) A new -non-voting-server
  option flag has been added for Consul servers to configure a server
  that does not participate in the Raft quorum.
- Upgrade Orchestration: (Consul Enterprise) Autopilot will
  automatically orchestrate an upgrade strategy for Consul servers
- Network Areas: (Consul Enterprise) A new capability has been added
  which allows operators to define network areas that join together two
  Consul datacenters.
- WAN Soft Fail: Request routing between servers in the WAN is now more
  robust by treating Serf failures as advisory but not final.
- WAN Join Flooding: A new routine was added that looks for Consul
  servers in the LAN and makes sure that they are joined into the WAN as
  well.
- Validate command: To provide consistency across our products, the
  configtest command has been deprecated and replaced with the validate
  command

IMPROVEMENTS:

- agent: Fixed a missing case where gossip would stop flowing to dead
  nodes for a short while.
- agent: Changed agent to seed Go's random number generator.
- agent: Serf snapshots no longer have the executable bit set on the
  file.
- agent: Consul is now built with Go 1.8.
- agent: Updated aws-sdk-go version (used for EC2 auto join) for Go 1.8
  compatibility.
- agent: User-supplied node IDs are now normalized to lower-case.
- agent: Added checks to enforce uniqueness of agent node IDs at cluster
  join time and when registering with the catalog.
- cli: Standardized handling of CLI options for connecting to the Consul
  agent.
- cli: Updated go-cleanhttp library for better HTTP connection handling
  between CLI commands and the Consul agent
- cli: The operator raft subcommand has had its two modes split into the
  list-peers and remove-peer subcommands.
- cli: Added an -id flag to the operator raft remove-peer command to
  allow removing a peer by ID.
- dns: Allows the .service tag to be optional in RFC 2782 lookups.
- server: Changed the internal EnsureRegistration RPC endpoint to
  prevent registering checks that aren't associated with the top-level
  node being registered.

BUG FIXES:

- agent: Fixed an issue with consul watch not working when http was
  listening on a unix socket.
- agent: Fixed an issue where checks and services could not sync
  deregister operations back to the catalog when version 8 ACL support
  is enabled.
- agent: Fixed an issue where agents could use the ACL token registered
  with a service when registering checks for the same service that were
  registered with a different ACL token.
- cli: Fixed consul kv commands not reading the CONSUL_HTTP_TOKEN
  environment variable.
- cli: Fixed an issue where prefixing an address with a protocol (such
  as 'http://' or 'https://') in -http-addr or CONSUL_HTTP_ADDR would
  give an error.
- cli: Fixed an issue where error messages would get printed to stdout
  instead of stderr.
- server: Fixed an issue with version 8 ACLs where servers couldn't
  deregister nodes from the catalog during reconciliation.
- server: Fixed an issue where servers could temporarily roll back
  changes to a node's metadata or tagged addresses when making updates
  to the node's health checks.
- server: Fixed an issue where the service name consul was not subject
  to service ACL policies with version 8 ACLs enabled.


(fhajny)