Metadata integration

[sbatchelder]

Allow model to include roi dimensions and other metadata into the classification process

[sbatchelder]

The preliminary work for this is ready:

• adjusting data loader to include metadata
• training + validation loops to include metadata

Remaining:

• modifying model forward method to accept a new series of input from the dataloader
• hooking up/merging new input layer with prexisting model layers (for inception_v3 model)

Later:

• Comparing this metadata feature against og model
• try out additional metadata beyond roi-dimensions