Simplify PyGMT Release process

.github/ISSUE_TEMPLATE/release_checklist.md

@@ -0,0 +1,36 @@
+---
+name: PyGMT release checklist
+about: Checklist for a new PyGMT release.
+title: 'Release PyGMT x.x.x'
+labels: 'maintenance'
+assignees: ''
+
+---
+
+**Release**: [v0.x.x](https://github.com/GenericMappingTools/pygmt/milestones/0.x.x)
+**Scheduled Date**: YYYY/MM/DD
+
+**Before release**:
+- [ ] Reserve a DOI on [Zenodo](https://zenodo.org)
+- [ ] Update Changelog
+
+**Release**:
+- [ ] Make a tag and push it to Github
+```
+git tag x.x.x
+git push --tags
+```
+- [ ] Go to [GitHub Release](https://github.com/GenericMappingTools/pygmt/releases) and make a release
+- [ ] Announce release on the GMT forum and [website](https://www.generic-mapping-tools.org) (News)
+- [ ] Upload the pygmt-v0.x.x.zip file to Zenodo
+
+**After release**:
+- [ ] Create branch 0.x for bug-fixes if this is a minor release (i.e. create branch 0.1 after 0.1.0 is released)
+- [ ] Commit changes to Github
+
+**3rd party update**:
+- [ ] Update conda-forge [pygmt-feedstock](https://github.com/conda-forge/pygmt-feedstock)
+
+---
+
+- [ ] Party :tada: (don't tick before all other checkboxes are ticked!)

.github/release-drafter.yml

@@ -0,0 +1,26 @@
+name-template: 'v$NEXT_PATCH_VERSION'
+tag-template: 'v$NEXT_PATCH_VERSION'
+categories:
+  - title: 'New Features'
+    label: 'feature'
+  - title: 'Enhancements'
+    label: 'enhancement'
+  - title: 'Documentation'
+    label: 'documentation'
+  - title: 'Bug Fixes'
+    label: 'bug'
+  - title: 'Maintenance'
+    label: 'maintenance'
+  - title: 'Deprecations'
+    label: 'deprecation'
+exclude-labels:
+  - 'skip-changelog'
+change-template: '* $TITLE (#$NUMBER) @$AUTHOR'
+template: |
+  [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3781524.svg)](https://doi.org/10.5281/zenodo.3781524)
+
+  ## Highlights
+
+  *
+
+  $CHANGES

.github/workflows/release-drafter.yml

@@ -0,0 +1,19 @@
+name: Release Drafter
+
+on:
+  push:
+    # branches to consider in the event; optional, defaults to all
+    branches:
+      - master
+
+jobs:
+  update_release_draft:
+    runs-on: ubuntu-latest
+    steps:
+      # Drafts your next Release notes as Pull Requests are merged into "master"
+      - uses: release-drafter/release-drafter@v5.8.0
+        with:
+          # (Optional) specify config name to use, relative to .github/. Default: release-drafter.yml
+          # config-name: my-config.yml
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

MAINTENANCE.md

@@ -81,6 +81,17 @@ There are a few steps that still must be done manually, though.
 
 ### Updating the changelog
 
+The Release Drafter Github Action will automatically keep a draft changelog at
+https://github.com/GenericMappingTools/pygmt/releases, adding a new entry
+every time a Pull Request (with a proper label) is merged into the master branch.
+This release drafter tool has two configuration files, one for the Github Action
+at .github/workflows/release-drafter.yml, and one for the changelog template
+at .github/release-drafter.yml. Configuration settings can be found at
+https://github.com/release-drafter/release-drafter.
+
+The drafted release notes are not perfect, so we will need to tidy it prior to
+publishing the actual release notes at https://www.pygmt.org/latest/changes.html.
+
 1. Generate a list of commits between the last release tag and now:
 
     ```bash