Enhancements to benchmarking

Hi,

I was thinking of adding some features & simplifying the benchmarking tool into a single line usage command line interface.

For example:

1. ‘mlpack-benchmark -ann -mlpack -github=#1123123’
2. ‘mlpack-benchmark -ann -shogun -github=#522323’
3. ‘mlpack-benchmark -ann -mlpack'

The following should be the parameters to this system:

1. The algorithm (-ann, -kmeans, -cnn)
2. The ML library (-mlpack, -shogun, -scikit)
3. GitHub commit (optional)
4. Local path to uncommitted library (-local=/some/path)
5. Which data sets to train on (-datasets=wine,iris)

The output should be the time it took to train on each data set, error rate, more specific
output on the algorithm itself (MSE, avg. time per epoch etc.)

This enhancement should also allow users to specify which commit of the library they wanna run the benchmark test on. Alternatively, they could specify a local commit to bench mark, to easily test uncommitted changes. Moreover, this program will automatically download & build the source of the library if required.

The issue names no files, tests, or entry points. Start by locating the existing benchmarking command and its library, dataset, and build integrations, then narrow the requested CLI and output behavior into a defined scope with acceptance criteria.