edit round overview heading
implement using store to delete fixed cost
Merge pull request #69 from open-app/fixedCosts

update round overview page with editable fixed costs
begin new contributors page
minor styling fix
add membership model and memberships store, resolve memberships for group-members page
minor edit to round contributors page style
Feature: Add/remove group members
remove unnecessary resolves
fix membership model
fix memberships store
add allocations store
add saving functionality to allocation model
update contributors functionality in round model
updating existing allocations on round contributors page now works
fix allocation model serialize
update round contributors page to work when no allocation already exists
fix round contributors controller usage of contributor objects to reflect previous changes
change allocation model to reflect API change