test_ram is low-level test that tests RAM pages allocation/mmapping.
As allocated pages are not integrated with virtmem (not added to any
file mapping and RAM->lru_list) the Page structs have to be explicitly
freed. Fixes e.g.

	Direct leak of 80 byte(s) in 1 object(s) allocated from:
	    #0 0x7ff29af46518 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xe9518)
	    #1 0x56131dc22289 in zalloc include/wendelin/utils.h:67
	    #2 0x56131dc225d6 in ramh_alloc_page bigfile/tests/../ram.c:41
	    #3 0x56131dc2a19e in main bigfile/tests/test_ram.c:130
	    #4 0x7ff29ac9f09a in __libc_start_main ../csu/libc-start.c:308