Removed duplicate simplejson on line 5 already on line 13

requirements.txt edited online with Bitbucket.

requirements.txt

@@ -2,7 +2,6 @@
 # Python pacakges that cannot be installed with pip (e.g. PyQt5, GDAL) are not included.
 # Usage: pip install -r requirements.txt
 numpy>=1.8
-simplejson
 dill
 rtree
 pyopengl