Add automated tests

Author: DanielRamirez404

tests/automated-tests.cpp

@@ -0,0 +1,40 @@
+#include "cppmenu.h"
+#include <iostream>
+#include <exception>
+
+void foo() {
+    return;
+} 
+
+int main()
+{
+    try
+    {
+        CppMenu::CommonMenu menu
+        {
+            "SAMPLE TITLE",
+
+            { 
+                { "Function Title", &foo, false }
+            },
+
+            true
+        };
+
+        if (false)
+            menu.run(); //not executing so that the building and testing log doesn't get erased in case of running ctest -V
+        
+        std::cout << "Automated tests passed.\n"
+                  << "You can include the cppmenu.h header file and use the CppMenu namespace.\n"
+                  << "You can try to run CppMenu-Tests executable to test the library's menus.\n";
+    }
+    catch (const std::exception& exception)
+    {
+        std::cerr << "CppMenu library's automated tests failed\n"
+                  << "Error: " << exception.what() << '\n';
+    
+        return 1;
+    }
+
+    return 0;
+}