GitLab

* Delete accuracy if exists in eval results.

* get global_step only if it exists in eval results

This will allow one to easily reproduce a benchmark by running with the flags.

* Combined imagenet and cifar-10 benchmarks

* Comments and epochs_between_evals.

* Added tuned tests and cleaned up benchmark flags

* Fix names.

* Return results and add images/sec hook.

* updated doc strings for return values.

* 128 to 256 batch for FP16 test

* added more doc strings to fix lint.