change memory usage display
using standard unix postfixes add unit test for display
also change doc for memory usage display change
for example GiB will be GB
@@ -2342,7 +2342,7 @@ Running `docker stats` on multiple containers
$ docker stats redis1 redis2
CONTAINER CPU % MEM USAGE/LIMIT MEM % NET I/O
redis1 0.07% 796 KiB/64 MiB 1.21% 788 B/648 B
- redis2 0.07% 2.746 MiB/64 MiB 4.29% 1.266 KiB/648 B
+ redis2 0.07% 2.746 MB/64 MB 4.29% 1.266 KB/648 B
The `docker stats` command will only return a live stream of data for running
