Prepare release: 2.0rc3 (metomi#2594)

* Prepare release 2.0rc3

Workflow: Release stage 1 - create release PR (Rose 2+ only), run: 9

* Tweak change log.

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Hilary James Oliver <[email protected]>

bump version number 2019.01.7 (metomi#2583)

Prevents Rose 2019 interacting with Cylc 8 workflows.

Merge pull request metomi#2565 from metomi/prepare-2.0rc2

Prepare release: 2.0rc2

Merge pull request metomi#2546 from metomi/prepare-2.0rc1

Prepare release: 2.0rc1

Merge pull request metomi#2496 from metomi/prepare-2.0b3

Prepare release: 2.0b3

Merge pull request metomi#2475 from metomi/prepare-2.0b2

Prepare release: 2.0b2

First Rose2 beta release

Rose release 62 - companion of cylc 7.8.7/7.9.2 and FCM 2019.09.0

Rose release 60 - companion of cylc 7.8.7/7.9.2 and FCM 2019.09.0