Update views.py to be compatible with the latest stable version of flask

[vixtordev]

When sending the file to the browser, it has to be new, it is currently achieved by this:

response = send_file(file_path, mimetype='text/plain', cache_timeout=0)

The latest stable version of Flask now, uses max_age . People can fix this themselves locally but its an inconvinience.

Hopefully this gets merged :)