Testing fixes

[mgalardini]

Some more changes added during testing, namely:

• Avoid conflicts in the /tmp directory if multiple users run the pipeline in the same machine
• Speed up tests by reducing the size of the reference proteome genomes (~5% of the original size)
• Swap sift for sequence_unet for the rare variants analysis

[mgalardini]

I've run the full test on a clean repository, and it completed in 65m21.817s, which is not that bad! If we can manage to use a much smaller database for eggnogg we would have an even better test