adding some model changes around paid plans

rowers/utils.py

@@ -426,6 +426,13 @@ class NoTokenError(Exception):
     def __str__(self):
 	return repr(self.value)
 
+class ProcessorCustomerError(Exception):
+    def __init__(self, value):
+        self.value=value
+
+    def __str__(self):
+        return repr(self.value)
+
 # Custom exception handler, returns a 401 HTTP message
 # with exception details in the json data
 def custom_exception_handler(exc,message):