Merge branch 'dev'

* dev:
  v0.5.0
  changes for v0.5.0
  Use `upper_90` as default timer field in statsd client
Merge branch 'dev'

* dev:
  v0.5.2
  Use node-ssdb own promisify
  v0.5.1
  Upgrade ssdb to v0.1.5
  Add connection pool
  Add `ssdb.size` to configs.toml
  Dump error stack on fatal error
  Strict alert conditions
  Limit dropdown menu to max height 560px
Add log debug on hipchat alerter
Fix typoe `stats` => `stat`