Add ability to add endpoints to the built API

[danbovey]

If you use redux-bees in a chunked application, the logic for many other pages can be chunked up into files that can be loaded later with Webpack JSONP but the object for API calls will be full of endpoints that won't be used - making the main chunk file larger.

So you should add the ability to call this function which would generate a new function, for example, API.getDifferentPosts() dynamically.

API.addEndpoints({
    getDifferentPosts: { method: get, path: '/path/to/different/apis' }
});