add nightly tests (#172)

This is just copied one-to-one from ChainRulesCore.

closes #160

Author: simeonschaub

.github/workflows/JuliaNightly.yml

@@ -0,0 +1,33 @@
+name: JuliaNightly
+# Nightly Version of Julia.
+# Runs on PRs and pushes to `master`, but seperate workflow to `CI`
+# to avoid inclusion in nightly cron build with failure notifications.
+on:
+  push:
+    branches: [master]
+    tags: ["*"]
+  pull_request:
+jobs:
+  test:
+    name: Julia Nightly - Ubuntu - x64
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: julia-actions/setup-julia@v1
+        with:
+          version: nightly
+          arch: x64
+      - uses: actions/cache@v2
+        env:
+          cache-name: julia-nightly-cache-artifacts
+        with:
+          path: ~/.julia/artifacts
+          key: ${{ env.cache-name }}-${{ hashFiles('**/Project.toml') }}
+          restore-keys: |
+            ${{ env.cache-name }}-
+      - uses: julia-actions/julia-buildpkg@latest
+      - uses: julia-actions/julia-runtest@latest
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v1
+        with:
+          file: lcov.info