Remove the normalize function

[Seth-Rothschild]

@bschreck

[codecov-io]

Codecov Report

Merging #140 into master will decrease coverage by 0.31%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #140      +/-   ##
==========================================
- Coverage   90.73%   90.42%   -0.32%     
==========================================
  Files          76       73       -3     
  Lines        7824     7768      -56     
==========================================
- Hits         7099     7024      -75     
- Misses        725      744      +19

Impacted Files	Coverage Δ
featuretools/entityset/entityset.py	90.44% <ø> (ø)	⬆️
featuretools/entityset/entity.py	79.77% <ø> (-10.53%)	⬇️
featuretools/entityset/base_entityset.py	91.11% <100%> (-0.05%)	⬇️
featuretools/primitives/primitive_base.py	90.1% <100%> (+4.15%)	⬆️
featuretools/entityset/timedelta.py	80.71% <100%> (-0.14%)	⬇️
featuretools/entityset/base_entity.py	76.64% <100%> (-2.52%)	⬇️
featuretools/entityset/relationship.py	82.6% <100%> (-0.38%)	⬇️
featuretools/variable_types/variable.py	81.7% <100%> (+2.63%)	⬆️
featuretools/synthesis/encode_features.py	94.54% <0%> (-3.5%)	⬇️
... and 7 more

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[kmax12]

Looks good to me. Merging