[benchmarks] Minimize the size of built images

[mcolmant]

Several optimisations can be applied to reduce the size of built images.

Docker commits each RUN command inside a new layer (which can take a non negligible amount of disk). It is thus important to clean (if possible) the image before the completion of the RUN command. One example could be to delete all intermediate compilation files just after the compilation (and not in a separate RUN as done currently).

You could see each layer of an image by using the command docker history [tag/id].

A guide for the best practices to build docker images is available here

The current virtual size of PARSEC-3.0 is 25 GB and should be considerably reduced.

[ouap]

Should be ok now