Remove unused package

Fig11_sfr.py

@@ -14,8 +14,6 @@ params = {'legend.fontsize': 'large',
          'ytick.labelsize':'large'}
 pylab.rcParams.update(params)
 
-from swiftsimio import load
-
 import sys
 sys.path.insert(0, "helpers/")
 from select_simulations_for_figures import Fig11_runnames as runnames