Activity due date changes

[corydbrown]

As a ConnectWise user, I want the default due date for activities to be 0 so that there's less of a chance I'll miss anything.

The current default is 7. Clients are more sensitive about this being 0, so let's have that be the default.

Also, let's investigate if we can have the start time be immediately after it's created.

Exit Criteria:

• Change default Activity due date from 7 to 0
• See if we can set the activity start time to the next 15-minute increment. For example, if the form was submitted at 12:04, the activity start time would be 12:15
• If we can do something similar to above, implement it

Trello: https://trello.com/c/t9xU9xl9/395-connectwise-forms-calendar-reminder-error

Ticket: https://pronto.zendesk.com/agent/tickets/304959