Smaller auth0 package

[prestontighe]

• Remove isomorphic-fetch (not being used)

[timwis]

I was under the impression isomorphic-fetch just attached itself to the window or global object, so that the fetch that's used later is defined.

[kbrandwijk]

@timwis You are right, it is used indeed. It could have been node-fetch however, because it doesn't run in the browser anyways. I would also use import fetch from 'node-fetch' so it's clear that it is actually being used.

[prestontighe]

Ah ok didn't know what it did. Creating a global variable from requiring a package seems like bad practice to me but o well. At least do import fetch from 'node-fetch' like you said @kbrandwijk .