Issue 19 - adding additional csv content types

[jawood1]

@abjerner initial pull request for #19

This has been seperated out from original pull request #22

I know you said this needs additional investigation any help I can provide let me know :)

Once again I've included for the content types initially:

• application/vnd.ms-excel
• text/csv

[abjerner]

Hi @jawood1

As discussed in #19 the list allowed content types is probably something that should be configurable. The solution for this is therefore a bit different, which is why I've closed this PR.

When reading some of the links you have provider, I'd still say that the problem is caused by incorrect file associations on the user system. But I don't really have any overview of how often users will have an incorrect file association. So the default configuration allows the following content types:

text/plain
text/x-csv
application/vnd.ms-excel
application/csv
application/x-csv
text/csv
text/comma-separated-values
text/x-comma-separated-values
text/tab-separated-values

I was a bit hesitant to allow too many content type, but the code also checks that the file extension is .csv, so the combination of the content types listed above and the .csv extension should be fine.

Thanks for your feedback and helping with discussing the issue 👍