Fix faker in requirements (#76)

Tests failed with
```
ImportError: The ``fake-factory`` package is now called ``Faker``.

Please update your requirements.
```
The `fake-factory` package was deprecated on December 15th, 2016.
Use the `Faker` package instead.

Author: ron8mcr

requirements.txt

@@ -2,5 +2,6 @@ dj-database-url==0.4.1
 # Can upgrade once we lose DJANGO1.7
 django-extensions==1.6.7
 factory-boy==2.7.0
+faker==0.7.7
 coverage==4.2
 mock==2.0.0