Unified getitem output for all tilers

Unified getitem output for all tilers: ConstStrideTiles, ConstSizeTiles

tiles = ConstSizeTiles(*args, **kwargs)
for extent, out_size in tiles:
    pass

and

tiles = ConstStrideTiles(*args, **kwargs)
for extent, out_size in tiles:
    pass

Please, note that in the previous version ConstSizeTiles provides only extent:

tiles = ConstSizeTiles(*args, **kwargs)
for extent in tiles:
    pass

Const stride/size tilings

• Const size tiling with examples etc
• Removed numpy from dependencies
• Added six as dependency

Released on pypi

v0.1.2

Update docs conf.py, Readme, tests and version

Package with docs online

• No code modifications
• Docs is available with readthedoc at http://imagetilingutils.readthedocs.io/en/latest/

First release v0.1

This is the first release