Peaceful-pie

New features:
- python 3.8 and python 3.9 supported now

Changes:
- `Simulation.RealStepSize` renamed to `Simulation.FixedDeltaTime`
- `Simulation.DedicatedRealStepSize` renamed to `Simulation.DedicatedFixedDeltaTime`

Update Simulation component interface:
<img width="463" alt="Screen Shot 2023-01-14 at 20 22 44" src="https://user-images.githubusercontent.com/123560/212504518-996dcc74-dc4d-4d80-ad9f-75f49504baaf.png">

Changes:
- throw exception with useful error message if no detectable tags provided to RayCasts
- no longer displays 'no json content received'
- added sliders to Inspector for Raycasts resolution and angle

Bug fixes:
- fixed bug with calculating ray angles in RayCasts

Changes:
- `UnityComms` is now cloudpickleable
- `UnityComms` will now call new rpc method `shutdownUnity()`, on a dedicated server that it has launched itself
- and `NetManager` implements this method
- including implementing it in a way that works on dedicated servers (looks like `Application.Quit()` doesn't work on dedicated servers)

Fixes:
- added `retry` into `UnityCommsFn` for use when calling a function using indexing notation `unity_comms['my_method']()`, or direct function call notation `unity_comms.my_method()`
- when running DungeonEscape using multiple processes, and when using option `--server-executable-path`, if use ctrl-c to exit, then on Ubuntu, the child Unity processes shutdown correctly now

Additions:
- added `py.typed` file, so that `mypy` works ok

Fixes:
- add `ResultClass` explicit parameter when using notation `unity_comms['method'](...)` or `unity_comms.method(...)`

Additions:
- can pass parameters directly into rpc call by name now, see below
- can use an indexer to call a method now, see below
- can directly call methods on the `UnityComms` object now, see below

Details

Before:

All calls went via `call_rpc`, giving the method name as a parameter, and the parameters as a dictionary:

Given:

unity_comms = UnityComms()

We could make calls like:

result = unity_comms.call_rpc(method='some_method', params_dict={"message": "Hello!"})


First update above: can pass in parameters directly by name:

result = unity_comms.call_rpc(method='some_method', message="Hello!")

Second update above: can use an indexer, to give the method name:

result = unity_comms['some_method'](message="Hello!")


Third update above: can directly call methods:

result = unity_comms.some_method(message="Hello!")


Whichever approach works well for you :)