Memory leaks on main menu.

[guilhemSmith]

> valgrind ./bomberman 
==13304== Memcheck, a memory error detector
==13304== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==13304== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==13304== Command: ./bomberman
==13304== 
[INFO]: create gui
[INFO]: Audio loaded.
[INFO]: exit game
[INFO]: exit SDL
==13304== 
==13304== HEAP SUMMARY:
==13304==     in use at exit: 240,420 bytes in 1,397 blocks
==13304==   total heap usage: 50,361 allocs, 48,964 frees, 1,074,875,793 bytes allocated
==13304== 
==13304== LEAK SUMMARY:
==13304==    definitely lost: 6,961 bytes in 7 blocks
==13304==    indirectly lost: 82,562 bytes in 474 blocks
==13304==      possibly lost: 0 bytes in 0 blocks
==13304==    still reachable: 150,897 bytes in 916 blocks
==13304==         suppressed: 0 bytes in 0 blocks
==13304== Rerun with --leak-check=full to see details of leaked memory
==13304== 
==13304== For counts of detected and suppressed errors, rerun with: -v
==13304== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 1)