Use upstream nose instead of a fork.

The multiprocessing issues we had seen previously do not appear
when we use our combination of plugin settings for multiprocessing.
This makes it unnecessary to use a fork.

requirements/edx/base.txt

@@ -134,6 +134,7 @@ freezegun==0.1.11
 mock-django==0.6.9
 mock==1.0.1
 moto==0.3.1
+nose==1.3.7
 nose-exclude
 nose-ignore-docstring
 nosexcover==1.0.7

requirements/edx/github.txt

@@ -33,9 +33,6 @@ git+https://github.com/edx/rfc6266.git@v0.0.5-edx#egg=rfc6266==0.0.5-edx
 # Used for testing
 -e git+https://github.com/gabrielfalcao/lettuce.git@b18b8fb711eb7a178c58574716032ad8de525912#egg=lettuce=1.8-support
 
-# nose fork needed for multiprocess support
-git+https://github.com/edx/nose.git@99c2aff0ff51bf228bfa5482e97e612c97a23245#egg=nose==1.3.7.1
-
 # Our libraries:
 -e git+https://github.com/edx/XBlock.git@a20c70f2e3df1cb716b9c7a25fecf57020543b7f#egg=XBlock
 -e git+https://github.com/edx/codejail.git@6b17c33a89bef0ac510926b1d7fea2748b73aadd#egg=codejail