formatUptime = uptime => {
    let parts = []
    let remaining = Math.round(uptime)

    if (remaining >= SECONDS_PER_DAY) {
        parts.push(`${Math.floor(remaining / SECONDS_PER_DAY)}d`)
        remaining = remaining % SECONDS_PER_DAY
    }

    if (remaining >= SECONDS_PER_HOUR) {
        parts.push(`${Math.floor(remaining / SECONDS_PER_HOUR)}h`)
        remaining = remaining % SECONDS_PER_HOUR
    }

    if (remaining >= SECONDS_PER_MINUTE) {
        parts.push(`${Math.floor(remaining / SECONDS_PER_MINUTE)}mn`)
        remaining = remaining % SECONDS_PER_MINUTE
    }

    parts.push(`${remaining}s`)

    return parts.join(' ')
}
Format uptime (seconds) to human readable output.

@param {Number} uptime
@returns {string}