Reintroduce the Content-Type header, deleted by mistake.

Author: afoucret

elastic_site_search/client.py

@@ -217,6 +217,7 @@ def _put(self, path, params={}, data={}):
 
   def _request(self, method, path, params={}, data={}):
     headers = {}
+    headers['Content-Type'] = 'application/json'
     headers['X-Swiftype-Client'] = CLIENT_NAME
     headers['X-Swiftype-Client-Version'] = VERSION
     if self.__username is not None and self.__password is not None: