[V3 RPC] Swap back to initial RPC library and hook into core commands (#1780)

* Switch RPC libs for websockets support

* Implement RPC handling for core

* Black reformat

* Fix docs for build on travis

* Modify RPC to use a Cog base class

* Refactor rpc server reference as global

* Handle cogbase unload method

* Add an init call to handle mutable base attributes

* Move RPC server reference back to the bot object

* Remove unused import

* Add tests for rpc method add/removal

* Add tests for rpc method add/removal and cog base unloading

* Add one more test

* Black reformat

* Add RPC mixin...fix MRO

* Correct internal rpc method names

* Add rpc test html file for debugging/example purposes

* Add documentation

* Add get_method_info

* Update docs with an example RPC call specifying parameter formatting

* Make rpc methods UPPER

* Black reformat

* Fix doc example

* Modify this to match new method naming convention

* Add more tests

requirements.txt

@@ -3,7 +3,7 @@ aiohttp>=2.0.0,<2.3.0
 appdirs==1.4.3
 raven==6.5.0
 colorama==0.3.9
-jsonrpcserver
+aiohttp-json-rpc==0.8.7
 pyyaml==3.12
 fuzzywuzzy[speedup]<=0.16.0
 Red-Trivia>=1.1.1