Use datetime.strptime tokens internally for parsing ISO 8601 week dates (#889)
Use datetime.strptime tokens internally for parsing ISO 8601 week dates (#889)

* a small test to play with source code

* replace  iso_to_gregorian method in parser with datetime.strptime

* remove import iso_to_gregorian

* a small test to play with source code

* replace  iso_to_gregorian method in parser with datetime.strptime

* remove import  iso_to_gregorian

* use tokens for ISO 8601
crsmithdev/arrow