return type of `create` cannot be named

https://github.com/developit/redaxios/blob/1c2d5846d0a2172e5dd77366a836404f6ce8f71e/src/index.js#L70

`redaxios` is not defined anywhere, so it cannot be used downstream. That is, it is impossible to define a function that takes the return type of `create` as a parameter.