chore: add github ci

.github/workflows/github-ci.yaml

@@ -0,0 +1,26 @@
+name: Github CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: git fetch --unshallow || true
+    - run: yarn install --frozen-lockfile
+    - run: npm run build
+    - run: npm run lint
+    - run: npm run test
+      env:
+        CI: true

spec/karma.config.js

@@ -24,7 +24,7 @@ module.exports = function (karma) {
     }
   }
 
-  if (!process.env.APPVEYOR) {
+  if (process.env.TRAVIS) {
     config.browsers.push('Firefox')
   }