Changing the source module "Networkmodel"

a)Working on a VM , would cause problems with importing of pyNN.utilities and its classes . It is not an issue with the code , but users might need to know it , for implementations . If similar importing issues occur on standard machines , please refer to (https://ncoghlan_devs-python-notes.readthedocs.org/en/latest/python_concepts/import_traps.html )  

b)Also , in the testModel.py file , there is no networkmodel module to import from , hence i have changed it to : ( from vogelsEtAl2011 import * )

Will be glad to hear your views on them .
Himanshu