[Feature Request] chevron should work with binary format

[alanyee]

import chevron

with open('file.mustache', 'r') as f:
    chevron.render(f, {'mustache': 'World'})

outputs Hello World, but

import chevron

with open('file.mustache', 'rb') as f:
    chevron.render(f, {'mustache': 'World'})

becomes TypeError: cannot unpack non-iterable int object