feat(uptime): replace plugin with sed

[vdbe]

The uptime plugin has some issue with minute formatting.

The sed command is based on https://stackoverflow.com/a/28353785.

$ bash uptimes
03:14:20 up 1 min,  2 users,  load average: 2.28, 1.29, 0.50
         new: 1m
         old: 1 min
04:12:29 up 59 min,  5 users,  load average: 0.06, 0.08, 0.48
         new: 59m
         old: 59 min
05:14:09 up  2:01,  5 users,  load average: 0.13, 0.10, 0.45
         new: 2h 01m
         old: 2h 01m
03:13:19 up 1 day, 0 min,  8 users,  load average: 0.01, 0.04, 0.05
         new: 1d 0m
         old: 1d 0 min
04:13:19 up 1 day,  1:00,  8 users,  load average: 0.02, 0.05, 0.21
         new: 1d 1h 00m
         old: 1d 1h 00m
12:49:10 up 25 days, 21:30, 28 users,  load average: 0.50, 0.66, 0.52
         new: 25d 21h 30m
         old: 25d 21h 30m

$ cat uptimes.sh 
#!/usr/bin/env bash

while read line; do
    echo "$line"
    echo -en "\t new: "
    echo "$line" | sed 's/^[^,]*up *//; s/, *[[:digit:]]* users.*//; s/ day.*, */d /; s/:/h /; s/ min//; s/$/m/'
    echo -en "\t old: "
    echo "$line" | awk -F, '{print $1,$2}' |
        sed 's/:/h /g;s/^.*up *//; s/ *[0-9]* user.*//;s/[0-9]$/&m/;s/ day. */d /g'
done <uptimes.txt

uptimes.txt

[89iuv]

looks good