[QRTR-78] Fixed up some Account and User formatting in the API, added separate post vs get Account method, and fixed plaid_client auth token bug.

api/mixins.py

@@ -0,0 +1,32 @@
+class ReadWriteSerializerMixin(object):
+    """
+    Overrides get_serializer_class to choose the read serializer
+    for GET requests and the write serializer for POST requests.
+
+    Set read_serializer_class and write_serializer_class attributes on a
+    viewset. 
+    """
+
+    read_serializer_class = None
+    write_serializer_class = None
+
+    def get_serializer_class(self):        
+        if self.action in ["create", "update", "partial_update", "destroy"]:
+            return self.get_write_serializer_class()
+        return self.get_read_serializer_class()
+
+    def get_read_serializer_class(self):
+        assert self.read_serializer_class is not None, (
+            "'%s' should either include a `read_serializer_class` attribute,"
+            "or override the `get_read_serializer_class()` method."
+            % self.__class__.__name__
+        )
+        return self.read_serializer_class
+
+    def get_write_serializer_class(self):
+        assert self.write_serializer_class is not None, (
+            "'%s' should either include a `write_serializer_class` attribute,"
+            "or override the `get_write_serializer_class()` method."
+            % self.__class__.__name__
+        )
+        return self.write_serializer_class