Remove/abstract-out need to install settings.json on the target system

To interact with zookeeper via ficus, the PC needs to have a **settings.json** file that exists somewhere on the machine. Let's consider a few alternatives:

* **settings.json** is bundled with the instrument-wrapper repository OR
* **settings.json** is not needed altogether

As-is, we make ficus harder to use on target PCs because they need to install a file (probably) outside of the scope of a github repository. It makes deployment more cumbersome because if fields change, we need to manually find and change these **settings.json** files in lock step.

Related: https://github.com/AllenNeuralDynamics/ficus/issues/38