Add try...except for non-mnist cases
Add try...except for non-mnist cases

From #77 as proposed by @shartoo.
superliuwanjia/DCGAN,carpedm20/DCGAN-tensorflow,carpedm20/DCGAN-tensorflow,superliuwanjia/DCGAN,Instassa/DCGAN-tensorflow,bxclib/DCGAN-tensorflow,superliuwanjia/DCGAN,Instassa/DCGAN-tensorflow,carpedm20/DCGAN-tensorflow,superliuwanjia/DCGAN,bxclib/DCGAN-tensorflow,bxclib/DCGAN-tensorflow,Instassa/DCGAN-tensorflow