Refactor getBinRanges to include a new option `auto(mlp)`

[kallewesterling]

See Helper_functions.getBinRanges: add other option: elif 'auto(mlp)'

def getBinRanges (dataframe, binTypeDict, numBinsDict):
    trainingDfDiscterizedRanges = []
    trainingDfDiscterizedRangesDict = {}

    # loop through variables in trainingDf (columns) to discretize into ranges according to trainingDf
    for varName in binTypeDict.keys():
        if binTypeDict[varName] == 'p':
            trainingDfDiscterizedRanges.append(percentile_bins(dataframe[varName], numBinsDict.get(varName)))  # adds to a list
            trainingDfDiscterizedRangesDict[varName] = percentile_bins(dataframe[varName], numBinsDict.get(varName))  # adds to a dictionary
        elif 'e':
            trainingDfDiscterizedRanges.append(bins(max(dataframe[varName]), min(dataframe[varName]),numBinsDict.get(varName)))  # adds to a list
            trainingDfDiscterizedRangesDict[varName] = bins(max(dataframe[varName]), min(dataframe[varName]),numBinsDict.get(varName))  # adds to a dictionary

    return trainingDfDiscterizedRangesDict