Unicode and Python-3 compatibility

[krmanish]

I think we should use Python-3 compatible code for unicode.

from future import unicode_literals

Found here and and all other places wherever required.

[faif]

@krmanish I agree. Those u should go away :)

[sara-02]

@faif @krmanish You can actually add your comment on the previous issue around Python3. #208.
This looks like a duplicate of the mentioned issue :)

[faif]

@sara-02 Good point, closing this ticket in favor of #208