Log Message:
## 0.8.4 (June 9, 2017)

FEATURES:
- agent: Added a method for transitioning to gossip encryption on an
  existing cluster
- agent: Added a method for transitioning to TLS on an existing cluster
- agent: Added support for RetryJoin on Azure
- agent: (Consul Enterprise) Added AWS server side encryption support
  for S3 snapshots using the snapshot agent.

IMPROVEMENTS:
- agent: Added a check which prevents advertising or setting a service
  to a zero address (`0.0.0.0`, `[::]`, `::`).
- agent: Allow binding to any public IPv6 address with `::`
- agent: Removed SCADA-related code for Atlas and deprecated all
  Atlas-related configuration options.
- agent: Added support for custom check id and name when registering
  checks along with a service.
- agent: Updated go-sockaddr library to add support for new helper
  functions in bind address templates (`GetPrivateIPs`, `GetPublicIPs`),
  new math functions, and to pick up fixes for issues with detecting
  addresses on multi-homed hosts.
- agent: Watches now reset their index back to zero after an error, or
  if the index goes backwards, which allows watches to recover after a
  server restart with fresh state.
- agent: HTTP health checks now upport custom method and headers.
- agent: Increased the graceful leave timeout from 5 to 15 seconds.
- agent: Added additional logging when the agent handles signals and
  when it exits.
- build: Added support for linux/arm64 binaries.
- build: Consul now builds with Go 1.8.3.
- ui: Added a sticky scroll to the KV side panel so the KV edit box
  always stays in place.

BUG FIXES:
- agent: Added defensive code to prevent agents from infecting the
  network coordinates with `NaN` or `Inf` values, and added code to
  clean up in environments where this has happened.
- api: Added code to always read from the body of a request so that
  connections will always be returned to the pool.
- build: Added a vendor fix to allow compilation on Illumos.
- cli: Fixed an issue where `consul exec` would return a 0 exit code,
  even when there were nodes that didn't respond.