benchmark memory

[dtrifiro]

It would be nice to be able to add memory benchmarks.

References:

• https://github.com/ionelmc/pytest-benchmark/issues/28#issuecomment-561960809
• https://github.com/iterative/dvc/wiki/Debugging,-Profiling-and-Benchmarking-DVC#memory-profiler
• https://github.com/pythonspeed/filprofiler

credits @daavoo

[dtrifiro]

Closing as this is a duplicate of https://github.com/iterative/dvc-bench/issues/129