Support for regular meeting that requires a minimum number of users (sports, exercise group, game etc)

[pflodo]

For a group of people that meet up say weekly at same time slot for a team sport there are only a small number of features that would make rallly a really good solution. This is a huge market in terms of different groups that need to manage regular rosters and meetups - there are sports specific solutions, but rallly is attractive through its simpleness and no fuss.

Features:

1. Support multiple weeks either by
   a. Repeating poll such as Allow users to duplicate a poll #445
   b. Support repeating dates within one permanent poll (say 4 weeks ahead and remove old dates from poll) similar to this: Auto-remove dates that are past #851
2. Setting max and minimum - eg 4 man kayaking would have minimum and maximum 4, casual soccer training would have minimum but maybe no max just more subs Cap on number of participants on a given date #155