v0.18

Improved support for HA alertmanager clusters (#224 #229)

Full changelog:

• #275 build(deps): update nodejs to 10.14.1 (@prymitive)
• #280 Build(deps): bump mobx from 5.6.0 to 5.7.0 in /ui (@dependabot-bot)
• #279 fix(ui): improve support for HA clusters (@prymitive)
• #278 fix(ui): don't show @alertmanager labels on HA setup (@prymitive)
• #277 build(deps): bump gopkg.in/yaml.v2 from 2.2.1 to 2.2.2 (@dependabot-bot)
• #276 build(deps): bump github.com/getsentry/raven-go from 0.1.1 to 0.2.0 (@dependabot-bot)