message: doc: update roadmap with proper v1 release date
diff: @@ -34,7 +34,7 @@ Ultimately, we're aiming for Terminal v1.0 to be feature-complete by Dec 2019, a
  | 2020-01-28 | Beta 1 | Pri 0/1/2 Bug fixes & polish |
  | 2020-02-25 | Beta 2 | Pri 0/1 Bug fixes & polish |
  | 2020-03-24 | RC | Pri 0 bug fixes |
  -| 2020-04-01 ? | v1.0 | Terminal v1.0 Release |
  +| 2020-05 | v1.0 | Terminal v1.0 Release |
  ## GitHub Milestones
  