add fields to conference/models.py
add fields to conference/models.py

malemburg/epcon,barrachri/epcon,PythonSanSebastian/epcon,matrixise/epcon,artcz/epcon,artcz/epcon,artcz/epcon,PythonSanSebastian/epcon,barrachri/epcon,EuroPython/epcon,barrachri/epcon,matrixise/epcon,malemburg/epcon,PythonSanSebastian/epcon,malemburg/epcon,matrixise/epcon,PythonSanSebastian/epcon,EuroPython/epcon,artcz/epcon,barrachri/epcon,malemburg/epcon,artcz/epcon,PythonSanSebastian/epcon,malemburg/epcon,EuroPython/epcon,matrixise/epcon,malemburg/epcon,barrachri/epcon,matrixise/epcon,barrachri/epcon,EuroPython/epcon,matrixise/epcon,PythonSanSebastian/epcon,artcz/epcon