Add support for lockfiles to n3fit and vp-setupfit
Created by: wilsonmr
input_folder is a required attribute of the environment class. To avoid conflict I have put the input_folder for n3fit inside of the replica path (<fitname>/nnfit/input
) and inside of filter output for vp-setupfit (<fitname>/filter/input
) just to prevent them overwriting each other
see NNPDF/reportengine#30