Update dependencies, add Prettier, testing on PR's (#65)

* Updates dependencies to the latest versions

* Update peer dependencies to Stencil v2 and above

* Adding github pipelines

* Adds prettier

.github/workflows/main.yml

@@ -0,0 +1,30 @@
+name: Node CI
+
+on:
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x]
+        stencil-version: [2.4.0, latest]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - name: npm install, build, and test
+      run: |
+        npm install
+        npm run build -- --ci
+        npm run test.ci
+      env:
+        CI: true