ci: enable GitHub Actions (#217)

.github/workflows/ci.yaml

@@ -0,0 +1,76 @@
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+name: ci
+jobs:
+  units:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [7, 8, 11]
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: ${{matrix.java}}
+    - run: java -version
+    - run: .kokoro/build.sh
+      env:
+        JOB_TYPE: test
+    - name: coverage
+      uses: codecov/codecov-action@v1
+      with:
+        name: actions ${{matrix.java}}
+  windows:
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: 8
+    - run: java -version
+    - run: .kokoro/build.bat
+      env:
+        JOB_TYPE: test
+  dependencies:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: 8
+    - run: java -version
+    - run: .kokoro/dependencies.sh
+  linkage-monitor:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: 8
+    - run: java -version
+    - run: .kokoro/linkage-monitor.sh
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: 8
+    - run: java -version
+    - run: .kokoro/build.sh
+      env:
+        JOB_TYPE: lint
+  clirr:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: 8
+    - run: java -version
+    - run: .kokoro/build.sh
+      env:
+        JOB_TYPE: clirr

.kokoro/build.bat

@@ -1,3 +1,3 @@
 :: See documentation in type-shell-output.bat
 
-"C:\Program Files\Git\bin\bash.exe" github/java-firestore/.kokoro/build.sh
+"C:\Program Files\Git\bin\bash.exe" %~dp0build.sh