Resolve "Add pop function"

Closes #6 (closed)

main.c

@@ -2,18 +2,16 @@
 
 int main(){
 	stack s;
-	int value = 0;
+	int value = 13;
 	stack_init(&s);
 
-	for (int i = 0; i < s.capacity; i++){
-		s.top += 1;
-		s.data[s.top] = i;
-		printf("push : %d\n", s.data[s.top]);
-	}
+	s.top += 1;
+	s.data[s.top] = value;
+
+	s.top += 1;
+	s.data[s.top] = value+1;
 	
-	// stack_is_empty(stack s)
 	stack_pop(&s, &value);
-	stack_peek(s, &value);
 
 	free(s.data);
 	s.data = NULL;