TypeError: memoryview: a bytes-like object is required, not 'str'

[Spugnam]

Hi, I am getting the error below when using the DOWNLOADER_MIDDLEWARES indicated in the ReadMe (I added a proxy list, etc..). Read a bunch of threads on SO but couldn't fix my issue.

Appreciate any help
thanks

Traceback (most recent call last):
File "/usr/local/Cellar/python3/3.6.3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/base64.py", line 517, in _input_type_check
m = memoryview(s)
TypeError: memoryview: a bytes-like object is required, not 'str'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/twisted/internet/defer.py", line 1386, in _inlineCallbacks
result = g.send(result)
File "/usr/local/lib/python3.6/site-packages/scrapy/core/downloader/middleware.py", line 37, in process_request
response = yield method(request=request, spider=spider)
File "/usr/local/lib/python3.6/site-packages/scrapy_proxies/randomproxy.py", line 70, in process_request
basic_auth = 'Basic ' + base64.encodestring(proxy_user_pass)
File "/usr/local/Cellar/python3/3.6.3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/base64.py", line 547, in encodestring
return encodebytes(s)
File "/usr/local/Cellar/python3/3.6.3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/base64.py", line 534, in encodebytes
_input_type_check(s)
File "/usr/local/Cellar/python3/3.6.3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/base64.py", line 520, in _input_type_check
raise TypeError(msg) from err
TypeError: expected bytes-like object, not str
2017-10-16 23:19:20 [scrapy.core.engine] INFO: Closing spider (finished)
2017-10-16 23:19:20 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'downloader/exception_count': 1,
'downloader/exception_type_count/builtins.TypeError': 1,
'finish_reason': 'finished