Build documentation using a Github action (#20)

Replace the Travis configuration for documentation building with a
Github action.

Author: martinholters

.github/workflows/Documentation.yml

@@ -0,0 +1,32 @@
+name: Documentation
+
+on:
+  push:
+    branches:
+      - develop
+    tags: '*'
+  pull_request:
+
+jobs:
+  build:
+    name: build on Julia ${{ matrix.julia-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        julia-version: ['1.0', '1.1', '1.2', '1.3', 'nightly']
+    steps:
+      - uses: actions/checkout@v2
+      - uses: julia-actions/setup-julia@v1
+        with:
+          version: ${{ matrix.julia-version }}
+      - name: Install dependencies
+        run: julia --project=docs -e 'using Pkg; Pkg.instantiate()'
+      - name: Build and deploy
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # For authentication with GitHub Actions token
+          DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }} # For authentication with SSH deploy key
+        run: julia --project=docs/ docs/make.jl
+      - uses: actions/upload-artifact@v1
+        with:
+          name: docs
+          path: docs/build

.travis.yml

@@ -15,19 +15,3 @@ notifications:
     on_start: never
 codecov: true
 coveralls: true
-jobs:
-  include:
-    - &docs
-      stage: "Documentation"
-      julia: 1.0
-      script:
-        - julia --project=docs/ -e 'using Pkg; Pkg.instantiate()'
-        - julia --project=docs/ docs/make.jl
-    - <<: *docs
-      julia: 1.1
-    - <<: *docs
-      julia: 1.2
-    - <<: *docs
-      julia: 1.3
-    - <<: *docs
-      julia: nightly