use specific object systematics variations for each background
update example of obj systematics
version bump
initialize object systematics dict to empty dict with 'signal' and 'background' keys
bugfix: fill backgroundobjsysts matrix only when needed
check size of background list and obj uncertainties before computing smearing (do not compute smearing when either one is missing).
add tests for background, background smearing and object systematics
Merge pull request #52 from gerbaudo/fixobjectsyst

Fixobjectsyst