test settings: Fix deprecation warnings
test settings: Fix deprecation warnings

RemovedInDjango20Warning: Old-style middleware using
settings.MIDDLEWARE_CLASSES is deprecated. Update your middleware and
use settings.MIDDLEWARE instead.

FutureWarning: `TemplateForHostMiddleware` is deprecated. Please
upgrade to the template loader. See: https://goo.gl/SzHPR4

FutureWarning: `TemplateForDeviceMiddleware` is deprecated. Please
remove it from your middleware settings.

gcushen/mezzanine-api,gcushen/mezzanine-api