Support for custom science Workflows

[phycodurus]

This is just an idea to support the defintion and execution of custom workflows. For example, if a workflow consist of steps such as:

1. receive alert
2. create target (or region)
3. perhaps identify targets of interest with that region
4. do analysis of target(s) perhaps to categorize, prioritize, or determine cadence of follow-up observations
5. make observations
6. analysis of follow-up observations
7. loop back to step 3 or ???

The idea is to provide a frame work with integration points where by a (perhaps yaml-defined) workflow could be started and tracked (perhaps with a Jenkins-like UI).

Again, this is just an idea.