Address reproducibility issues

[skrakau]

No description provided.

[AntoniaSchuster]

I'm not sure what is meant here, but I discovered that when I run the test_tiny multiple times, the file entrez_data/entities_proteins.entrez.tsv is not always the same, e.g. I ran it three times and two out of three times it has
1189 lines and one time it has 1154 lines. Can someone explain this?

[skrakau]

Hi @AntoniaSchuster,
what you described turned out to be a bug. Great that you discovered this :) I created a PR: nf-core/metapep#3

This issue originally meant, for example, that the Entrez download is not reproducible: for instance, new assemblies, sequences, proteins might be uploaded to NCBI which then will be downloaded and processed by the pipeline, causing not reproducible results (this is a general issue with the Entrez download). One could think about avoiding this by saving some intermediate results in the future.