Elixir DogStatsD client is in
Merge pull request #257 from DataDog/alq666/elixir

Elixir DogStatsD client is in
Remove duplicate elixir entries
Change contributor name for Elixir statsd client.
Switch to network checks page.

- Update copy where needed.
- Redirect old service checks page to network checks page, with a
  message.
- Update links in header, etc
Clean up the process check docs and reference process monitors.
Uncomment the process monitors docs
Merge branch 'master' into staging
Merge branch 'conor/monitors' into staging