Remove dependency over six

jsignature/widgets.py

@@ -3,7 +3,6 @@
     with jSignature jQuery plugin
 """
 import json
-import six
 
 from django.template.loader import render_to_string
 from django.forms.widgets import HiddenInput
@@ -17,6 +16,13 @@ from jsignature.settings import JSIGNATURE_DEFAULT_CONFIG
 JSIGNATURE_EMPTY_VALUES = validators.EMPTY_VALUES + ('[]', )
 
 
+try:
+    from django.utils import six
+    string_types = six.string_types
+except ImportError:
+    string_types = str
+
+
 class JSignatureWidget(HiddenInput):
     """
     A widget handling a signature capture field with with jSignature
@@ -54,7 +60,7 @@ class JSignatureWidget(HiddenInput):
         """ Prepare value before effectively render widget """
         if value in JSIGNATURE_EMPTY_VALUES:
             return "[]"
-        elif isinstance(value, six.string_types):
+        elif isinstance(value, string_types):
             return value
         elif isinstance(value, list):
             return json.dumps(value)