CSV Parser enclosure should be user definable

[AaronHolbrook]

I am running into an issue where there is a comma within a cell but it is properly enclosed in a quotation marks.

https://github.com/SoapBox/laravel-formatter/blob/master/src/Parsers/CsvParser.php#L18

However, due to the setEnclosure being hardcoded to a pipe character, the parsing is breaking and ignoring the enclosure.

I propose allowing users of this package to simply define the enclosure to be whatever they need.