update to python3

Author: nibrahimb1993

onesignal/__init__.py

@@ -1,3 +1,3 @@
 __author__ = 'waqas'
 
-from onesignal_client import OneSignal
+from .onesignal_client import OneSignal

onesignal/onesignal_client.py

@@ -47,7 +47,7 @@ def __init__(self, user_auth_key, app_id=None, version='v1'):
         """
         self.app_id = app_id
         self.user_auth_key = user_auth_key
-        assert isinstance(version, basestring), 'version is not valid'
+        assert isinstance(version, "".__class__), 'version is not valid'
         self.api_url = BASE_URL + version
 
     def get_headers(self):

setup.py

@@ -6,6 +6,7 @@ def readme():
     with open('README.rst') as f:
         return f.read()
 
+
 setup(
     name='onesignal',
     packages=find_packages(exclude=['tests*']),