index.js
function replace(reducers, scope, defaultState) {
  remove(scope);
  add(reducers, scope, defaultState);
}
function replace(reducers, scope, defaultState) {
  remove(scope);
  add(reducers, scope, defaultState);
}
replace - replace with new reducers

@param  {object} reducers     reducer functions
@param  {string} scope        state data scope
@param  {mixed} defaultState  default state of scope
@returns {undefined}