**CHANGELOG:**
* rewrite of the instrument server to be a true server using RPyC (https://rpyc.readthedocs.io/en/latest/index.html) to implement remote procedure calls.
- it allows for the driver-specific code to reside solely on the instrument server machine and allows exceptions on the instrument server to propagate through to the spyrelet (i.e. client), which simplifies debugging.
- it has an interactive shell interface directly to the the instrument server; it can be used to reload devices, restart the server, etc.
- a gateway connection to the instrument server can be made using the `InservGateway` class to connect to a server and interface with drivers; this removes the dependence on MongoDB to interface with device drivers
* improvement to handling of config files, now requiring two config files - one for the client and one for the instrument server, with a command line tool `nspyre-config` to add config files to the nspyre path
- device drivers for the instrument server can now be referenced in the config file by either: 1) using python local scope dot notation (e.g. `examples.LantzSignalGenerator`) or 2) via a file system path to the python file and the name of the class.
* MongoDB is no longer installed as a windows service; the seeming cause of issues for several users
- there is now a subpackage `mongodb` which contains scripts `start_mongo_win.bat` and `start_mongo_unix.sh` for restarting MongoDB
- MongoDB is now installable as a dependency of nspyre when installing using conda - the preferred method of installation
- there is also a command line tool 'nspyre-mongodb', which calls the appropriate scripts from above, will stop any currently running `mongod` instance, remove the database files, and restart `mongod`.
* spyrelets are now loaded from file paths rather than directly from the python scope, which allows users to have spyrelets that are separate from the nspyre code
* compatibility fixes to work with the currently maintained version of Lantz https://github.com/lantzproject/lantz
* update of dependencies, python support, and install steps; complete rewrite of setup tools implementation
* various restructuring and reformatting of codebase