Adyen Python API Library 2.2.0

#94 [PW-1184] Add codeowers file for GitHub, remove validation and fixing failed te…
#91 [PW-1701] Added the xapikey in http client request for call api
#89 Fix coverage command
#88 App name can be empty
#87 Xapi key for recurring
#84 [PW-1636] Fix travis build and hmac tests
#80 Install wheel needed for pycurl
#79 [PW-1595] Add HMAC validation on all libraries. Add method to validate hmac
#78 Mutable types used as defaults