Clean Dataset
Clean Dataset

- all_util, inq_last_12m
    + Drop features (all observations contain null/missing values)
- revol_util
    1. Remove the percent sign (%) from string
    2. Convert to a float
- earliest_cr_line, issue_d
    + Convert to datetime data type.
- emp_length
    1. Strip leading and trailing whitespace
    2. Replace '< 1' with '0.5'
    3. Replace '10+' with '10.5'
    4. Fill null values with '-1.5'
    5. Convert to float
vnaidu/loan-status,vnaidu/loan-status