Move from Travis to GHA (test now, publish soon)

Author: pimterry

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+name: CI
+on: push
+jobs:
+  build:
+    name: Build & test
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 14.6
+
+      - name: Get npm cache directory
+        id: npm-cache
+        run: |
+          echo "::set-output name=dir::$(npm config get cache)"
+      - uses: actions/cache@v2
+        with:
+          path: ${{ steps.npm-cache.outputs.dir }}
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+
+      - run: npm ci
+
+      - run: npm run build
+      - run: npm run test
+      - run: npm run test:release
+
+      - uses: actions/upload-artifact@v2
+        with:
+          name: distributables
+          path: build/dist/*
+          if-no-files-found: error