scaffold solution source

src/2020/17.c

@@ -1,7 +1,10 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "input.h"
 
 void advent2020day17(void) {
+  char *input = get_input("input/2020/17");
   printf("Solution for Day 17 of 2020 is not completed yet\n");
+  free(input);
 }