a few more contributors

CONTRIBUTORS.rst

@@ -3,8 +3,13 @@ Original Authors
 ================
 
 * Matthew Westcott matthew.westcott@torchbox.com
+* David Cranwell david.cranwell@torchbox.com
+* Karl Hobley karl.hobley@torchbox.com
+* Helen Chapman helen.chapman@torchbox.com
 
 Contributors
 ============
 
+* Balazs Endresz balazs.endresz@torchbox.com
+* Neal Todd neal.todd@torchbox.com
 * Paul Hallett (twilio) hello@phalt.co