Make the order of the parameters determanistic

The URL parameters should be deterministic as the full URL is used as the key for caching. If the non-ordered dictionary is used the caching will miss even when a value has been stored.

prismic/connection.py

@@ -42,7 +42,8 @@ def get_json(url, params=None, access_token=None, cache=None, ttl=None, request_
         request_handler = get_using_requests
     if access_token is not None:
         full_params["access_token"] = access_token
-    full_url = url if len(full_params) == 0 else (url + "?" + urlparse.urlencode(full_params, doseq=1))
+    sorted_params = OrderedDict(sorted(full_params.items(), key=lambda t: t[0]))
+    full_url = url if len(full_params) == 0 else (url + "?" + urlparse.urlencode(sorted_params, doseq=1))
     cached = cache.get(full_url)
     if cached is not None:
         return cached
@@ -70,5 +71,9 @@ def get_max_age(headers):
     if expire_header is not None:
         m = re.match("max-age=(\d+)", expire_header)
         if m:
-            return int(m.group(1))
+            # The Prismic API is sending very high expeiery times (10 years) for articles, which
+            # makes it seem like it's using milliseconds rather than seconds. Some caching libraries
+            # (including AppEngine Memcache) sees this 10 year value as an error and refuses to
+            # store or retreive the cached value
+            return int(m.group(1)) / 1000
     return None