Default boulder attempt type to "Send"

[emilyg1709]

Send is generally more common than Flash - would be helpful if boulder attempt type defaulted to this value

[DavidWeisberg1]

Hi! Would it be alright if I could be assigned to this issue? This would be my first issue and it seems like a good one to get acquainted with the repository. I think I also need the API keys to be able to login locally, so I'll send an email to Viet.