Include sleep into library

tasks/tasks.c

@@ -1,11 +1,13 @@
 #include "library.h"
 
 int task2(void) {
-    puts("Hello World from task 1\n");
+    puts("Hello World from task 2\n");
+    sleep(4);
     return 0;
 }
 
 int task1(void) {
-    puts("Hello World from task 2\n");
+    puts("Hello World from task 1\n");
+    sleep(2);
     return 0;
 }