update last released timestamp to visually connect it more to the latest version box (#3481)
update last released timestamp to visually connect it more to the latest version box (#3481)

* update last released timestamp to visually connect it more to the latest version box

* display date as before and use border color defined in colours.scss

* add 'Last released:' to package header date status badge

* keep the style simple WRT #1988

dstufft/warehouse,dstufft/warehouse,pypa/warehouse,pypa/warehouse,dstufft/warehouse,pypa/warehouse,pypa/warehouse,dstufft/warehouse