ci: standardize FF CI (#63)

* ci: split unit and conformance ci

Signed-off-by: Grant Timmerman <[email protected]>

* ci: disable java 12/13

Signed-off-by: Grant Timmerman <[email protected]>

Author: grant

.github/workflows/ci.yaml

@@ -0,0 +1,22 @@
+name: Java Unit CI
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [
+          11.x
+          # 12.x,
+          # 13.x
+        ]
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK ${{ matrix.java }}
+      uses: actions/setup-java@v1
+      with:
+        java-version: ${{ matrix.java }}
+    - name: Build with Maven
+      run: (cd functions-framework-api/ && mvn install)
+    - name: Test
+      run: (cd invoker/ && mvn test)