add __version__ to package

Author: Alex Schworer

zencoder/__init__.py

@@ -2,3 +2,6 @@
 from core import ZencoderResponseError
 
 from core import Account
+
+from core import __version__
+

zencoder/core.py

@@ -3,8 +3,6 @@
 from urllib import urlencode
 from datetime import datetime
 
-LIB_VERSION = '0.5.2'
-
 # Note: I've seen this pattern for dealing with json in different versions of
 # python in a lot of modules -- if there's a better way, I'd love to use it.
 try:
@@ -21,6 +19,8 @@
         from django.utils import simplejson
         json = simplejson
 
+__version__ = '0.5.2'
+
 class ZencoderError(Exception):
     pass
 
@@ -67,7 +67,7 @@ def headers(self):
             'Content-Type': 'application/{0}'.format(content_type),
             'Accept': 'application/{0}'.format(content_type),
             'Zencoder-Api-Key': self.api_key,
-            'User-Agent': 'zencoder-py v{0}'.format(LIB_VERSION)
+            'User-Agent': 'zencoder-py v{0}'.format(__version__)
         }
 
         return headers