Setup github actions

.github/workflows/android.yml

@@ -0,0 +1,35 @@
+name: EhViewer
+
+on: 
+ push:
+    branches:
+    - master
+
+jobs:
+  linux:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+      - uses: actions/cache@v1
+        with:
+          path: ~/.gradle/caches
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+      - name: Build
+        env:
+          KEYSTORE_PASS: ${{ secrets.KEYSTORE_PASS }}
+          ALIAS_NAME: ${{ secrets.ALIAS_NAME }}
+          ALIAS_PASS: ${{ secrets.ALIAS_PASS }}
+        run: |
+          ./gradlew assembleRelease
+      - uses: actions/upload-artifact@master
+        name: Upload artifact
+        with:
+          name: EhViewer
+          path: app/build/outputs/