Are global headers possible?

Hi there, thank you for unirest!

See following example on how we are defining the header information:
```
const unirest = require('unirest');

class RouterService {

private auth = 'Basic sdofihsdfjkn3873kajsd‘;
private dataURL = 'http://backend-xyz‘;

getData() {
return unirest.get(`${dataURL}/data`)
.headers({'Authorization': this.auth});
}

postData() {
return unirest.post(`${dataURL}/data`)
.headers({'Authorization': this.auth});
}

}
```
Is there a way to set the headers information globally? The goal is not to define the header values for each and every request on a express route.

Thank you in advance.

Start by tracing the unirest.get and unirest.post entry points and how their .headers calls are applied. Compare this with the Express-route usage described in the issue; done means the supported global-header behavior and its request-level interaction are defined, implemented, and tested.

Written by the indexing model from the issue text.