Type error in the official rest_api example code

[journeast]

I am a new FAB user here, and found a minor but frustrating error in the official documentation.

• https://flask-appbuilder.readthedocs.io/en/latest/rest_api.html
• Flask-AppBuilder/docs/rest_api.rst

I was trying to follow through the above rest_api example, and copy the exact code below to my editor but it did not work. It turned out that it is just a simple type error. It should use [route_base] instead of [base_route], please correct this asap so as not to turn off new users.

`from flask_appbuilder.api import BaseApi, expose
from . import appbuilder

class ExampleApi(BaseApi):

base_route = '/newapi/v2/nice'

@expose('/greeting')
def greeting(self):
    return self.response(200, message="Hello")

appbuilder.add_api(ExampleApi)`

[fedepad]

@journeast I submitted a PR to fix that. Thanks for spotting it!