Add C++ HelloWorld example and corresponding CI job

.gitlab-ci.yml

@@ -1,3 +1,15 @@
-hello-world:
+build:gcclatest:
+  image: gcc:latest
+  stage: build
   script:
-    - echo "Hello World"
+    - g++ src/helloworld.cpp -o helloWorld
+  artifacts:
+    paths:
+      - helloWorld
+
+test:gcclatest:
+  image: gcc:latest
+  script:
+    - ./helloWorld
+  dependencies:
+    - build:gcclatest

src/helloworld.cpp

@@ -0,0 +1,6 @@
+#include <iostream>
+
+int main(){
+    std::cout << "Hello World!" << std::endl;
+    return 0;
+}