Remove unneeded six dependency (was used for Python 2) (#90)

Co-authored-by: Marius Kleidl <marius@transloadit.com>

.pylintrc

@@ -302,7 +302,7 @@ init-import=no
 
 # List of qualified module names which can have objects that can redefine
 # builtins.
-redefining-builtins-modules=six.moves,past.builtins,future.builtins,builtins,io
+redefining-builtins-modules=builtins,io
 
 
 [FORMAT]

setup.py

@@ -10,7 +10,6 @@
     author='Ifedapo Olarewaju',
     install_requires=[
         'requests>=2.18.4',
-        'six>=1.11.0',
         'tinydb>=3.5.0',
         'aiohttp>=3.6.2'
     ],

tests/test_fingerprint.py

@@ -1,7 +1,6 @@
+import io
 import unittest
 
-import six
-
 from parametrize import parametrize
 
 from tusclient.fingerprint import fingerprint
@@ -21,7 +20,7 @@ def setUp(self):
     def test_get_fingerpint(self, filename: str):
         with open(filename, "rb") as f:
             content = f.read()
-        buff = six.BytesIO()
+        buff = io.BytesIO()
         buff.write(content)
         buff.seek(0)  # reset buffer postion before reading
 
@@ -38,7 +37,7 @@ def test_get_fingerpint(self, filename: str):
     def test_unique_fingerprint(self, filename: str):
         with open(filename, "rb") as f:
             content = f.read()
-        buff = six.BytesIO()
+        buff = io.BytesIO()
         buff.write(content + b's')  # add some salt to change value
         buff.seek(0)  # reset buffer postion before reading
 

tusclient/storage/interface.py

@@ -2,11 +2,9 @@
 Interface module defining a url storage API.
 """
 import abc
-import six
 
 
-@six.add_metaclass(abc.ABCMeta)
-class Storage(object):
+class Storage(object, metaclass=abc.ABCMeta):
     @abc.abstractmethod
     def get_item(self, key):
         """