Add testing of output

.github/workflows/sandbox_ubuntu.yml

@@ -0,0 +1,33 @@
+---
+name: sandbox_ubuntu
+"on":
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  maven-build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        java: [11, 13]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up JDK
+        uses: actions/setup-java@v1
+        with:
+          java-version: ${{ matrix.java }}
+      - uses: actions/cache@v1
+        with:
+          path: ~/.m2/repository
+          key: ${{ runner.os }}-jdk-${{ matrix.java }}-maven-${{ hashFiles('**/pom.xml') }}
+          restore-keys: |
+            ${{ runner.os }}-jdk-${{ matrix.java }}-maven-
+      - name: Build it with Maven
+        run: mvn -B test
+      - name: Test it
+        run: ./run.sh 7 | python3 test.py

.github/workflows/sandbox.yml → .github/workflows/sandbox_windows.yml

@@ -1,18 +1,19 @@
 ---
-name: sandbox
+name: sandbox_windows
 "on":
   push:
     branches:
       - master
   pull_request:
     branches:
       - master
+
 jobs:
   maven-build:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [windows-latest, ubuntu-latest]
+        os: [windows-latest]
         java: [11, 13]
     steps:
       - uses: actions/checkout@v2

test.py

@@ -0,0 +1,3 @@
+test_str = input()
+print(f"The output is:\n{test_str}")
+assert test_str == "7th Fibonacci number is 13"