Dataset unit test

[niravshah241]

In unit test for dataset:

• Add testing for MultiGPU case
• Add check for error between original dataset and after normalisation and denormalisation

In unit test for training, validation, error analysis and online phase:

• Add multiGPU case

Add unit test for:

• Add test for Error analysis
• Add test for online phase
• Add test for Error analysis (Distributed)
• Add test for online phase (Distributed)
• Add test for Error analysis (MultiGPU)
• Add test for online phase (MultiGPU)