End to End Project - Bikes Assessment - Defining some utility functions

We shall be defining some utility function which shall be used later on in the project

set_day(df): assigns day names to each of the rows in the dataset.
mnth_cnt(df): count of months from the start of the time series
display_scores(scores): Function used to calculate the mean and deviation of observed scores from cross-validation of models

Please do not edit anything in the functions.