[51216209] can only set offer_accepted to true when filled_seat < total_seat

Signed-off-by: Henry Chen <hchen@vmware.com>
Merge branch 'master' of https://github.com/vmw-tmpst/heroapp-LetsHire into filled_seat
Display error message as Red

Signed-off-by: Henry Chen <hchen@vmware.com>
Merge branch 'master' of https://github.com/vmw-tmpst/heroapp-LetsHire into filled_seat
Merge pull request #253 from Henry-CF/filled_seat

[51216209] can only set offer_accepted to true when filled_seat < total_seat