Don't send Content-Type in the request - that header applies to respo…

…nses.

We could send "Accept: application/json", but that is the default,
and since we vary on Accept, we can increase the cache hit rate
by either always sending the default Accept header, or never sending it.
I'm proposing the latter.

Also, don't send Accept-Language if the client doesn't define a language.
Again, if all clients do this, we get a better hit rate.

gapipy/client.py

@@ -14,7 +14,7 @@
     'application_key': os.environ.get('GAPI_APPLICATION_KEY'),
     'api_root': os.environ.get('GAPI_API_ROOT', 'https://rest.gadventures.com'),
     'api_proxy': os.environ.get('GAPI_API_PROXY', ''),
-    'api_language': os.environ.get('GAPI_LANGUAGE', 'en'),
+    'api_language': os.environ.get('GAPI_LANGUAGE'),
     'cache_backend': os.environ.get('GAPI_CACHE_BACKEND', 'gapipy.cache.SimpleCache'),
     'cache_options': {'threshold': 500, 'default_timeout': 3600},
     'debug': os.environ.get('GAPI_CLIENT_DEBUG', False),

gapipy/request.py

@@ -34,11 +34,12 @@ def _request(self, uri, method, data=None, options=None, additional_headers=None
             url = url.replace(api_proxy, '')
 
         headers = {
-            'Content-Type': 'application/json',
+            # Why send the default?  'Accept': 'application/json',
             'User-Agent': '{0}/{1}'.format(__title__, __version__),
             'X-Application-Key': self.client.application_key,
-            'Accept-Language': self.client.api_language,
         }
+        if self.client.api_language:
+            headers['Accept-Language'] = self.client.api_language
         if additional_headers:
             headers.update(additional_headers)