Remove snakefood and our usage of it.

Unfortunately snakefood is not supported in python3 so I'm removing it
and the tools built on top of it for now as they are not in active use.

If you're looking at this wishing it still existed,

Check out https://github.com/bwohlberg/jonga or https://pypi.org/project/findimports/

requirements/edx/development.in

@@ -17,7 +17,6 @@ click                               # Used for perf_tests utilities in modulesto
 django-debug-toolbar==1.8           # A set of panels that display debug information about the current request/response
 edx-sphinx-theme                    # Documentation theme
 pyinotify                           # More efficient checking for runserver reload trigger events
-snakefood                           # Lists dependencies between Python modules, used in scripts/dependencies/*
 sphinx==1.8.5                       # Pinned because 2.0.0 release requires Python '>=3.5' but current Python is 2.7.12
 vulture                             # Detects possible dead/unused code, used in scripts/find-dead-code.sh
 modernize                           # Used to make Python 2 code more modern with the intention of eventually porting it over to Python 3.

requirements/edx/development.txt

@@ -303,7 +303,6 @@ simplejson==3.16.0
 singledispatch==3.4.0.3
 six==1.12.0
 slumber==0.7.1
-snakefood==1.4
 snowballstemmer==1.9.1    # via sphinx
 social-auth-app-django==2.1.0
 social-auth-core==1.7.0