Add unittest

SMILEBASIC/main.d

@@ -32,3 +32,11 @@ int main(string[] argv)
     }*/
     return 0;
 }
+
+unittest
+{
+    auto petitcomputer = new PetitComputer();
+    petitcomputer.run(true, "TEST.txt", false, true);
+    assert(petitcomputer.lastError is null);
+}
+