feat: add a gh action for publishing example on every PR

Author: Trancever

.github/workflows/publish-each-pr.yml

@@ -0,0 +1,48 @@
+name: Expo Review
+on: [pull_request]
+jobs:
+  publish:
+    name: Install and publish
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+
+      - name: Setup Expo
+        uses: expo/expo-github-action@v5
+        with:
+          expo-version: 3.x
+          expo-username: ${{ secrets.EXPO_CLI_USERNAME_PAPER }}
+          expo-password: ${{ secrets.EXPO_CLI_PASSWORD_PAPER }}
+          expo-cache: true
+
+      - name: Get yarn cache
+        id: yarn-cache
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+      
+      - name: Check yarn cache
+        uses: actions/cache@v1
+        with:
+          path: ${{ steps.yarn-cache.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
+
+      - name: Install dependencies
+        run: yarn bootstrap
+
+      - name: Publish Expo app
+        working-directory: ./example
+        run: expo publish --release-channel=pr-${{ github.event.number }}
+
+      - name: Comment on PR
+        uses: unsplash/comment-on-pr@master
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          msg: The mobile version of example app from this branch is ready! You can [see it here](https://expo.io/@react-native-paper/react-native-paper-example?release-channel=pr-${{ github.event.number }}).