Bump version to 0.4.0

[oscarbenjamin]

No description provided.

[oscarbenjamin]

I intend to merge this, push a 0.4.0 tag and then push the wheels and sdist to PyPI.

[oscarbenjamin]

I've just pushed this to PyPI but when I downloaded the wheel on Linux it crashed:

$ python test/test.py 
test_pyflint...OK
Illegal instruction (core dumped)

On OSX all tests and doctests passed. I'm going to test Windows now...

[oscarbenjamin]

On OSX all tests and doctests passed. I'm going to test Windows now...

Windows is fine as well. So the problem is just Linux. (The one thing I didn't test!)

[oscarbenjamin]

I've deleted the Linux wheels from PyPI. Now someone using pip install python-flint on Linux goes back to building from source as before.

Further investigation needed but it's late and I need to go to bed.