aliasmgr: use `T.TempDir` to create temporary test directory
aliasmgr: use `T.TempDir` to create temporary test directory

Signed-off-by: Eng Zer Jun <e94bff687675f33b892ede8d3a0a0eab27d6715c@gmail.com>

aakselrod/lnd,aakselrod/lnd