Istallation command amendment

[SotiriosVasileiadis]

Hi Blake et al,

Many thanks for this amazing tool!

Tried to install according to the mamba commands... e.g.

mamba create -n sourceapp --file path/to/SourceApp/dependencies/sourceapp.yml

and came across the following error:

could not parse '- bioconda' in: dependencies/sourceapp.yml

CondaValueError: could not parse '- bioconda' in: dependencies/sourceapp.yml

Seems that this command parses all lines as packages. Adding the "env" flag fixed that:

mamba env create -n sourceapp --file path/to/SourceApp/dependencies/sourceapp.yml