Merge pull request #33 from Panmax/fix_python2_unicode

修复 python2 alert 不能传 unicode 的bug

jpush/push/payload.py

 import re
+import sys
 
 # Valid autobadge values: auto, +N, -N
 VALID_AUTOBADGE = re.compile(r'^(auto|[+-][\d]+)$')
 
 
+PY2 = sys.version_info[0] == 2
+
+if not PY2:
+    string_types = (str,)
+else:
+    string_types = (str, unicode)
+
+
 def notification(alert=None, ios=None, android=None, winphone=None):
     """Create a notification payload.