MNT: Remove '_norm' from two variables
MNT: Remove '_norm' from two variables

The variables 'past_intensity_norm' and 'future_intensity_norm' are used
to normalize the correlation, they themselves are not normalized.
Putting '_norm' in the name of the variable is confusing, as one would
naturally expect these variables to be normalized.

danielballan/scikit-xray,licode/scikit-beam,scikit-xray/scikit-xray,CJ-Wright/scikit-beam,yugangzhang/scikit-beam,yugangzhang/scikit-beam,tacaswell/scikit-beam,Nikea/scikit-xray,tacaswell/scikit-xray,tacaswell/scikit-beam,Nikea/scikit-xray,tacaswell/scikit-beam,CJ-Wright/scikit-beam,danielballan/scikit-xray,tacaswell/scikit-xray,licode/scikit-xray,licode/scikit-beam,scikit-xray/scikit-xray,ericdill/scikit-xray,licode/scikit-beam,danielballan/scikit-xray,scikit-xray/scikit-xray,ericdill/scikit-xray,tacaswell/scikit-xray,licode/scikit-xray,ericdill/scikit-xray,yugangzhang/scikit-beam,CJ-Wright/scikit-beam,Nikea/scikit-xray,licode/scikit-xray