TimesheetSync initial version

[rngadam]

TimesheetSync should synchronize arbitrary spreadsheet by pushing them to an API endpoint of a document store as JSON document. The API endpoint is connected to a PostgreSQL database.

TODO

• [x] fix export of date with start, stop hours
  • https://stackoverflow.com/questions/17715841/how-to-read-the-correct-time-values-from-google-spreadsheet
• [x] send/store timezone with utc time
  • http://blog.untrod.com/2016/08/actually-understanding-timezones-in-postgresql.html
• [x] automatically retrieve headers and mapping from the first row of the sheet
• [x] configurable sheet (or auto-discover sheets that follow rows/columns inputs)