started work on backend

backend/venv/lib/python3.6/site-packages/libfuturize/fixes/fix_basestring.py

@@ -0,0 +1,17 @@
+"""
+Fixer that adds ``from past.builtins import basestring`` if there is a
+reference to ``basestring``
+"""
+
+from lib2to3 import fixer_base
+
+from libfuturize.fixer_util import touch_import_top
+
+
+class FixBasestring(fixer_base.BaseFix):
+    BM_compatible = True
+
+    PATTERN = "'basestring'"
+
+    def transform(self, node, results):
+        touch_import_top(u'past.builtins', 'basestring', node)