Discord.py dep update 3.1 (#2587)

* Dependency update

discord.py==1.0.1
websockets<7

[style]
black==19.3b0

[Docs]
jinja==2.10.1
urllib3==1.24.2

Changes related to breaking changes from discord.py have also been made
to match

As of this commit, help formatter is back to discord.py's default

redbot/core/commands/help.py

@@ -0,0 +1,23 @@
+from discord.ext import commands
+from .commands import Command
+
+__all__ = ["HelpCommand", "DefaultHelpCommand", "MinimalHelpCommand"]
+
+
+class _HelpCommandImpl(Command, commands.help._HelpCommandImpl):
+    pass
+
+
+class HelpCommand(commands.help.HelpCommand):
+    def _add_to_bot(self, bot):
+        command = _HelpCommandImpl(self, self.command_callback, **self.command_attrs)
+        bot.add_command(command)
+        self._command_impl = command
+
+
+class DefaultHelpCommand(HelpCommand, commands.help.DefaultHelpCommand):
+    pass
+
+
+class MinimalHelpCommand(HelpCommand, commands.help.MinimalHelpCommand):
+    pass