Support for st_blocks field

[albrycht]

Is your feature request related to a problem? Please describe.
I have a code that crawls filesystem. One of most important field that I read from stat is st_blocks (see: https://docs.python.org/3/library/os.html#os.stat_result.st_blocks)
Without that field my code fails with: AttributeError: 'FakeStatResult' object has no attribute 'st_blocks'

I know that theoretically, it doesn't have to be there but I haven't met POSIX filesystem that wouldn't have that field yet.

Describe the solution you'd like
Add st_blocks field to FakeStatResult.

Describe alternatives you've considered
The only alternative I see right now is not to use pyfakefs and mock os calls by myself.

[mrbean-bremen]

I guess it would be enough if the result would just be something like st_size / 512 + 1?

[albrycht]

Result should be int so I would suggest st_size // 512 + 1.

[mrbean-bremen]

Of course, that was what I meant - ok, I will see what I can do, maybe I will get to it over the weekend.

[mrbean-bremen]

Implemented in master now - please check!