Ensure options are passed to fetch()

[jtm240]

This PR fixes an issue where arguments are not being passed to fetch().

The project Readme states that it is possible to provide arguments to realtime(), but only the URL is being passed to fetch(). It is necessary to be able to supply arguments to fetch so that authentication (e.g. cookies) can be used when making calls to an endpoint that requires a valid user session.

If I've overlooked something, please let me know!

[perliedman]

Woops, nice catch! Thanks! 👍

[marianomd]

Dist folder still has old version where options aren't passed to fetch.

[brittanecrow]

Could someone provide an example of how to attach an authorization token header? I have not been able to achieve it. Here is what I am trying:

this.mapRealtime = L.realtime({
url: this.getRealtimeUrl(),
crossOrigin: true,
headers: {'authorization': 'token'},
type: 'json',
}, {

the authorization shows up but it appears the token is not being attached. Thank you!