Improvements to collect Reportback Quantity

[aaronschachter]

• Including a comma breaks things. Description: https://trello.com/c/BfVzkJKR
• Adding text along with the number breaks ("About 15", "78 dunks done")
• Submitting spelled out word of a number, oh hello https://github.com/DoSomething/count-von-count

[aaronschachter]

Tested this out with CampaignBot -- we don't get the behavior described in the Trello card (which was opened for the legacy reportback endpoint), but the check for quantity fails if user includes a comma.