* master: (21 commits)
  Fix issues with pdf-js dependencies
  fix missing changelog entries for security release on 2017-01-23
  Update top bar issues icon
  Fix order of CI lint ace editor loading
  Fix spec
  Fix spec
  Fix spec
  Add changelog
  fix
  Add a spec for concurrent process
  Add changelog
  essential
  add CHANGELOG.md for !13208
  adjust user contribution calendar time formatting
  fix rubocop violations 👮
  fix mysql syntax for date INTERVAL arithmatic
  add tests for proper timezone date grouping within ContributionsCalendar
  adjust timezone for date grouping in contributions calendar
  use timezone-aware Date.current instead of Date.today in ContributionsCalendar class
  display system timezone underneath activity calendar
  ...