parseDate must specify right timezone

[svera]

Alpha Vantage times are in US/Eastern timezone. time.Parse() consider times to be in UTC, so time.ParseInLocation() must be used instead.

Check https://golang.org/pkg/time/#ParseInLocation for more information.

[svera]

In order to make this future proof, right solution would be to get the timezone data from result metadata, which comes in this format:

"Meta Data": {
        "1. Information": "Intraday (5min) open, high, low, close prices and volume",
        "2. Symbol": "MSFT",
        "3. Last Refreshed": "2018-08-31 15:55:00",
        "4. Interval": "5min",
        "5. Output Size": "Compact",
        "6. Time Zone": "US/Eastern"
    },
...

but as code is currently getting information using CSV format this is not available.