Add support for memory benchmarking

Profiles the memory usage and adds the corresponding information to the final json records.

Check [this](http://facs2.nopcode.org:5984/_utils/document.html?facs/6454e0822e48c768b02b036a44190721) doc as an example :-)

**Important note:** Requires the installation of the latest version of memory_profiler, download and install from [github](https://github.com/fabianp/memory_profiler).