`read()` - unused and appears not to work

[clach04]

py-sds011/sds011/__init__.py

Line 158 in 4d3380a

def read(self):

Wondering if a PR to remove this is a good idea. I spent some time with this and couldn't get it to work. Documented query() worked fine.

[romintomasetti]

I think that read() is to be used in active reporting mode.