Simple conda requirements and docker image for nextflow pipeline

[chasemc]

First- I have most all the nextflow stuff in ~/Autometa/nextflow now, with only a false-config in the main directory ~/Autometa/ so that someone can pull the pipeline directly from nextflow.

I was thinking of making another, simple requirements.txt and dockerfile within the/Autometa/nextflow directory that are specific for running the nextflow pipeline. They would be simple: likely only including nf-core, nextflow, aspera.

The main reason is nextflow and/or nf-core are required to be installed in order for the pipeline to run but I don't think should be in the mostly-python oriented https://github.com/KwanLab/Autometa/blob/dev/requirements.txt

Thoughts?

[evanroyrees]

This may be easier to review under a pull request with your code changes. This way the context of your changes and the discussion are all in one place and up to date.

[chasemc]

Fixed by #157