fix(unicode): Import unicode_literals in every file

[adityahase]

Ran this script

import os
files = os.popen("git ls-files | grep \.py$ | xargs grep -L 'unicode_literals'").read().split()
for filename in files:
    new_content = None
    with open(filename) as f:
        content = f.readlines()
        if len(content):
            if content[0] == "from __future__ import print_function\n":
                new_content = ["from __future__ import print_function, unicode_literals\n"] + content
            else:
                new_content = ["from __future__ import unicode_literals\n"] + content
    if new_content:
        with open(filename, "w") as f:
            f.writelines(new_content)

Basically check if every .py file does from __future__ import unicode_literals if not do so.

[sagarvora]

https://travis-ci.org/frappe/frappe/jobs/482862437#L1557

[adityahase]

travis-ci.org/frappe/frappe/jobs/482862437#L1557

Passes now