mapbox/dyno — pull request #46 by mick (2014-10-22 22:40:34+00:00)
Title: allow for deleting items from sets

allows for deleting elements from sets with syntax like:

````
// Given a dynamo item:
{
someattr: ['foo', 'bar', 'baz']
}

// Delete like:
{
delete: {someattr: ['foo', 'bar']}
}

// Resulting item in dynamo:
{
someattr: ['baz']
}

````