Improve launch script

[tanaes]

This adds capability to easily launch a 'wet' test run, simply by doing:

oecophylla workflow --test

You can also provide other workflow parameters to test specific things, like testing a particular module:

oecophylla workflow --test qc

or testing in a particular workflow context:

oecophylla workflow --workflow-type torque --cluster-config cluster.json --test qc

what do you think @mortonjt? I went back and forth a ton of times on how best to do this, but this seemed most parsimonious.

[tanaes]

@mortonjt: good ideas, implemented.

[tanaes]

@mortonjt @tkosciol wanna merge?