Python 2.7 incompatibility in POST requests

[bluefish6]

version 1.2.0 in a66b74d#diff-60bc6d0e1237e90fd352225f9b3b997dR253 introduced a way to send POST requests that causes incompatibility with python 2.7, which can be easily averted by using encode('utf-8') instead of bytes():

change from:

payload = bytes(self._assemble_quoted_pairs(api_params), encoding='utf_8')

to:

payload = self._assemble_quoted_pairs(api_params).encode('utf_8')

Please change it so it will still work in Python 2. I know that Python 2 is already EOL, but the workaround is too easy to implement to break the compatibility.

[ruiyang-emailage]

@bluefish6
Thank you for your suggestions, we're testing it now

[ruiyang-emailage]

@bluefish6
Done and pushed to PyPI
https://pypi.org/project/emailage-official/1.2.2/