v0.3.1

Major changes:

• Generated a numeric patient id for OMOP-standardization. (Issue #15 )
• Added some insight for running times of each scripts. (as suggested in Issue #24 )
• Simplified the structure of paths.json
• Fixed inconsistency in datetimes of OMOP tables : some datetime columns contained the date, other contained the time of day. Now they all contain the full datetime. Issue #26

Minor changes:

• Added unit_concept_id to auxillary_files/user_input/timeseries_variables.csv
• Fixed harmless SettingWithCopy warning happening in database_processing/dataprocessor.py

Thanks to @mostafaalishahi, and @xinyuejohn for their contribution to the project.