Version 0.2.3
* New container for guru trades
* Bug in insider trades example fixed
* Ignore ',' as thousands separator in numbers provided as strings
* New container for insider trades
* New container for guru picks
* New guru portfolio container added

Version 0.2.2
* New container for stock summary added
* New type HexNum added. This was required to represent colors which are hex numbers delivered
  as of type Number is the hex representation does contain digits only (e.g. 204060), 
  otherwise as string (e.g. "2a4b6f")

Version 0.2.1
* New data structure for key ratios
* Reformatting of some files

Version 0.2.0 (since major update since 0.1.5)
* One example for each API function, ordered by the section number as they appear in the GuruFocus 
  documentation https://www.gurufocus.com/api.php. However, proper deserializing into proper structs
  is a TODO.
* Errors will show more information on the cause of the error as given by GuruFocus
* Dates use now chrono::NaiveDate, since the GuroFocus API does not provide any time zone information

