Use 'page_query_param' for pagination instead of hard coded page (#312)

* Use 'page_query_param' for pagination instead of hard coded page

*** What
- Use self.page_query_param to determine the query parameter to use for
  pagination
- Set the default page_query_param to 'page'
- Freeze fake-factory version to 0.7.4

*** Why
- Allow the use of different page query parameters to do pagination
- The latest version of fake-factory is now depreciated:
  https://pypi.python.org/pypi/fake-factory/9999.9.9

* Remove unneeded page_query_param default

* Add documentation for default page_query_param

Author: Eric Hurst

docs/usage.md

@@ -31,8 +31,10 @@ REST_FRAMEWORK = {
 
 If `PAGE_SIZE` is set the renderer will return a `meta` object with
 record count and a `links` object with the next, previous, first, and last links.
-Pages can be selected with the `page` GET parameter. Page size can be controlled
-per request via the `PAGINATE_BY_PARAM` query parameter (`page_size` by default).
+Pages can be selected with the `page` GET parameter. The query parameter used to
+retrieve the page can be customized by subclassing `PageNumberPagination` and
+overriding the `page_query_param`.  Page size can be controlled per request via
+the `PAGINATE_BY_PARAM` query parameter (`page_size` by default).
 
 ### Serializers
 

rest_framework_json_api/pagination.py

@@ -20,7 +20,7 @@ def build_link(self, index):
         if not index:
             return None
         url = self.request and self.request.build_absolute_uri() or ''
-        return replace_query_param(url, 'page', index)
+        return replace_query_param(url, self.page_query_param, index)
 
     def get_paginated_response(self, data):
         next = None
@@ -75,10 +75,10 @@ def get_last_link(self):
     def get_first_link(self):
         if self.count == 0:
             return None
-        
+
         url = self.request.build_absolute_uri()
         return remove_query_param(url, self.offset_query_param)
-    
+
     def get_paginated_response(self, data):
         return Response({
             'results': data,
@@ -95,4 +95,4 @@ def get_paginated_response(self, data):
                 ('next', self.get_next_link()),
                 ('prev', self.get_previous_link())
             ])
-        })
+        })