Lucinda Williams isn’t easily intimidated, but it would be hard for any musician not to shudder at the task before her. With only three days to work, she tackled an album of Beatles covers — one of the best-known catalogs in modern music — and recorded it at the Abbey Road studio in London where most of the originals were made some 60 years earlier. The result is out on Friday, the seventh of the “Lu's Jukebox” series of cover albums, and the first to be made available to streaming services. Williams tackled late-period Beatles music, including “While My Guitar Gently Weeps,” “Let it Be” and “The Long and Winding Road.”