Internet sanity check

[sm13]

This is in a way related to #1. Either find out how to handle that based on the error messages from the current calls, or add a way to check whether the device has internet access.

The former seems a bit more robust to me, and it means no reading file system files or running external commands.

[sm13]

Perhaps this is not something that rePocket should do, but rather something that script can do. For instance:

#!/bin/bash

function offline_check
{
    ping 8.8.8.8 -c 1 -t 60 > /dev/null 2>&1

    return $?
}

if [[ offline_check -eq 0 ]]
then
    # We're online!
    /home/root/.local/bin/rePocket

    exit 0
else
    exit 1
fi