Move calculator to proper folder.
Standard Score Calculation

Mean = Average of all absolute value of Observed - Expected values.
StdDev = Standard Deviation of all Observed - Expected values

For each X = O - E, perform the following calculation:

Standard Score = (X - Mean) / StdDev

Verification:
 1. Run python3 normalized_bias_calculator.py.
 2. Check data in SubstitutionAnlysResults.xlsx

**Note: Using the meaning on the input data set:
2SubstitutionAnlysML_INPUT.xlsx produced symmetrical results for transitions
e.g. A -> T, T -> A were the same value.
Merge pull request #3 from phoenixcoder/dev

Standard Score Calculation