Migrate CI from travis to github actions.

Author: harrysarson

.github/workflows/ci.yml

@@ -0,0 +1,49 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - "main"
+  pull_request:
+
+jobs:
+  main:
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        node-version: [14.x]
+
+    env:
+      ELM_HOME: '${{ github.workspace }}/elm-stuff/elm-home'
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-node@v1
+        with:
+          node-version: "${{ matrix.node-version }}"
+
+      - name: Cache node_modules
+        id: cache-node_modules
+        uses: actions/cache@v2
+        with:
+          path: node_modules
+          key: node_modules-${{ matrix.os }}-${{ matrix.node-version }}-${{ hashFiles('package-lock.json') }}
+
+      - name: Cache ELM_HOME
+        uses: actions/cache@v2
+        with:
+          path: '${{ env.ELM_HOME }}'
+          key: elm-${{ matrix.os }}-${{ hashFiles('elm-tooling.json', 'elm/**/elm.json', 'example-*/**/elm.json', 'tests/**/elm.json') }}
+
+      - name: Install elm-tooling CLI
+        if: steps.cache-node_modules.outputs.cache-hit != 'true'
+        run: npm install --no-save elm-tooling
+
+      - name: elm-tooling install
+        run: npx --no-install elm-tooling install
+
+      - name: test
+        run: npx -c ./tests/run-tests.sh

.travis.yml

@@ -0,0 +1,6 @@
+{
+    "tools": {
+        "elm": "0.19.1",
+        "elm-test-rs": "1.0.0"
+    }
+}