NOTES

➤ http "https://api.bitfinex.com/v2/candles/trade:1m:tBTCUSD/hist" > candles.json

2018-02-10T14:14:00Z
...
2018-02-10T12:16:00Z
2018-02-10T12:15:00Z

#!!! symbol must be uppercase

➤ http "https://api.bitfinex.com/v2/candles/trade:1m:tBTCUSD/hist?end=1391213400000&limit=3"
just setting &end works, start doesnt have to be present, it will return minute values ending
at END.
In above case 3 values before END

Maximum Limit of values in api response
=======================================

1000 values

Above that it returns:

	HTTP/1.1 500 Internal Server Error
	[
		"error",
		10020,
		"limit: invalid"
	]

Rate Limit
==========
If an IP address exceeds 90 requests per minute to the REST APIs, the requesting
IP address will be blocked for 10-60 seconds and the JSON response {"error": "ERR_RATE_LIMIT"}
will be returned.

Our rate limit policy can vary in a range of 10 to 90 requests per minute
depending on some factors (e.g. servers load, endpoint, etc.).

worst case: 6 req/min (1 req every 10sec)
best case: 1,5 req/sec --> to be on safe side we make 1 req/sec

Maintenance
===========
When in maintenance few API endpoints (eg. books, ...) will return a maintenance error to prevent you to use potentially inconsistent data.
["error", 20060, "maintenance"]