no-unicode_literals

The use of from __future__ import unicode_literals has been deemed an anti-pattern. The problems with it are:

• It makes it so one can’t jump into the middle of a file and know whether a bare literal string is a byte string or text string. The programmer has to first check the top of the file to see if the import is there.
• It removes the ability to define native strings (a string which should be a byte string on python2 and a text string on python3) via a string literal.
• It makes for more context switching. A programmer could be reading one file which has unicode_literals and know that bare string literals are text strings but then switch to another file (perhaps tracing program execution into a third party library) and have to switch their understanding of what bare string literals are.