Create a setTypes func to override default status

[cyrilf]

The setTypes function allows the user to override the default status.

For instance in my case, I don't use "FAILURE" but "ERROR".
With this PR, I could do the following:

import { setTypes, createFormAction } from 'redux-form-saga';

setTypes(["REQUEST", "SUCCESS", "ERROR"]);

const login = createFormAction("account/LOGIN");

Currently my two options are:

• Fork this repo

• Do the following:

export const LOGIN = "account/LOGIN"
function loginAction({ email, password }) {
  return { type: LOGIN, payload: { email, password } }
}

export const LOGIN_SUCCESS = "account/LOGIN_SUCCESS"
export const LOGIN_ERROR = "account/LOGIN_ERROR"

const login = createFormAction(loginAction, [LOGIN_SUCCESS, LOGIN_ERROR])

And I have to define my own loginSuccess and loginError because the library doesn't generate them automatically anymore

export function loginSuccess(access_token, user) {
  return { type: LOGIN_SUCCESS, payload: { access_token, user } }
}
export function loginError(error) {
  return { type: LOGIN_ERROR, error: true, payload: error }
}

which make this library really less attractive for me..