Preventing front running attack

[VamsiKrishnaCommits]

As I was skimming through the code , I realised that the code misses how to deal with front runners. (Refer to this article if you do not know what it means : https://medium.com/codechain/front-running-attacks-on-blockchain-1f5ba28cd42b) . I guess all we can do is , give the owner of the contract the ability to set the gas price and limit it so that everyone will have an equal chance at their transaction getting processed.