lk | adds none option to client bike

app/views/clients/_fields.html.haml

@@ -53,7 +53,7 @@
   .form-group
     = f.label "Bike:", class: "col-sm-2 control-label"
     .col-sm-10
-      = f.select :bike_id, options_for_select( Bike.available_for_freecyclery.collect{|b| [ b.name, b.id ]}, @client.bike_id )
+      = f.select :bike_id, options_for_select( Bike.available_for_freecyclery.collect{|b| [ b.name, b.id ]}, @client.bike_id ), {include_blank: 'None'}
 
   .form-group
     = f.label "Agency:", class: "col-sm-2 control-label"