v0.4.0

Changed

• Renamed the project to vigil. The binary is now vigil (was mta), the
  Go module is github.com/simtabi/vigil, the service identifier/display name are
  vigil/Vigil, and all config/runtime directories use vigil
  (~/.config/vigil, ~/.local/state/vigil; %AppData%\vigil etc.). Release
  artifacts are now vigil_<os>_<arch>.

Upgrade notes

• This is effectively a fresh install. From a 0.3.x (mta) install: remove the
  old service first (mta uninstall, or mta self uninstall --purge), then
  install vigil and re-run vigil config wizard (config does not migrate from
  ms-teams-activity automatically). For the Graph engine, vigil auth login
  again. mta upgrade cannot cross the rename — install vigil fresh.

Full Changelog: v0.3.1...v0.4.0