Update version number just to fix markdown rendering on pypi...

Update version

Merge pull request chainer#19 from mitmul/update-v4

Update v4

Merge pull request chainer#7 from chainer/add-mxnet-check

Add mxnet test

Remove .DS_Store

Update README

Merge pull request chainer#2 from mitmul/beta

Add many functions and tests

Fix install requires