Fisher GAN + Recurrent Highway Network + TTUR

[NickShahML]

This PR consists of the following changes:

1. Fisher GAN
2. Recurrent highway network with multiplicative integration and normalizing tanh
3. Two Time Scale ADAM (this has been set as default)

I have kept as much naming conventions the same as much as possible. One big change made is that all the gru names are replaced with rnn as it allows us to swap different type of rnn cells much more easily assuming they have a state size of n.

On my text editor (sublime), there were some weird spacing issues when I first pulled your repo. Hopefully this doesn't conflict with your editor.

In the meantime, I'm considering cramer gan and have made a corresponding branch on my repo.