Support name-of-conda-environment in /bin/seamless

[sjdv1982]

To indicate the name of the conda environment in which the command is to be executed. Must be known to the assistant/deployment machine(s). Most assistants should be able to deal with that, if only by preprending "conda activate" (even the micro-assistant could do that). Conforms to the dogma that environments don't influence the value of the result.

[sjdv1982]

UPDATE: should be very easy to add for mini-assistant. Not so much for the others.