Adyen Python API Library 1.3.0

Features:
#42 Add support for Third Party Payout service

Fixes:
#39 Fixed issue when raw_response is empty.
#40 Added GitHub templates for issues and PRs
#41 PW-279: Refactor code to PEP8 standards
#45 Move constants to settings file and raise error on KeyError
#46 code optimizations
#50 deleted unused, rephrased names