Ensure that response object from WPS includes HTTP header info

[agstephens]

Ensure that response object from WPS includes HTTP header info:

• Return: using names from HTTP headers: "location", "content-type", "content-length" etc.
• Use standards defined here: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers
• and maybe the auth token as well.

[cehbrecht]

I have updated the nginx config to show the content-type for netcdf. I don't know about Content-Location. It does not show up in the headers.

Example in notebook:
https://nbviewer.jupyter.org/github/bird-house/birdy/blob/master/notebooks/examples/roocs-demo.ipynb

[agstephens]

We should double-check what ECMWF want us to include.