Catch fatal errors from server

[brianmay]

Fixes #8

Notes:

• I have not tested this yet. What could possible go wrong.
• Authentication errors will undergo the same treatment. Not sure if this is good or bad. Maybe it might be good.
• I hope I didn't miss any function calls... I don't think I did.
• Actually, not sure if we want to log all errors. Due to the frequency of the life360 server producing 5xx errors.

Possibly we should somehow distinguish different errors, and call node.debug(...) on the 5xx errors.

[brianmay]

I actually find looking for things in node-red documentation difficult. So this may not be correct.

• Do I call node.err() or node.error()? Where is this function documented?
• What does this function do exactly?
• Does the function turn the node red?
• Does the function treat the error as an unhanded error?

I noticed this code, which I just changed also, I imagine this would result in a similar error loop. It probably should not be an error.

if (circles.length == 0) {
    throw new Error("No circles in your Life360.");
}

[brianmay]

Now testing... But not seeing any errors. Might have to somehow fake a server error if no real server errors.

[hepcat72]

WRT auth errors, it's probably fine. There was a special character issue in one person's password awhile back where it may have been helpful to have that feedback (instead of it silently not working).

[brianmay]

I am going to close this in favour of #10. But if #10 has unexpected problems, feel free to reopen.