Export positions as Yahoo Finance portfolio

[mortenscheel]

I found out it's pretty easy to generate a csv file from my eToro positions and import it in Yahoo Finance.

The csv structure is pretty simple:

Column name	Data from	Note
Symbol	EtoroAsset.SymbolFull	To upper case
Trade Date	EtoroPosition.OpenDateTime	YYYYMMDD format
Purchase Price	EtoroPosition.OpenRate
Quantity	EtoroPosition.Amount / EtoroPosition.OpenRate	Amount of shares
Comment		Optional

I would send a PR, but I don't know the best way to add Symbol to EtoroPosition.
The response should probably have these headers:

Content-Type: text/csv
Content-Disposition: attachment;filename=portfolio.csv