__future__ imports for Python 3 compatibilty

[aayux]

• Python 3 style division to resolve bug in Generate features(features.npy) Problem-Flickr30K #24.
• Other __future__ imports for Python 3 compatibility.

Finally, this could also break intended behaviour in some places so:

• Test for forward and backward compatibility.

[aayux]

@jishan900: Any discussions in this thread should be limited to the title, and this is not a related issue. We'd be happy to help but you must please open a new issue.