Remove (supervisor) opts from Omnibot.Plugin opts, update Plugin.Supervisor to use :one_for_all strategy by default

Plugin opts no longer contains options for the supervisors that watch
plugins, and said supervisors now adopt the one_for_all strategy. This
is because these servers *generally* need one another to stay alive.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

lib/plugin/plugin.ex

@@ -1,5 +1,5 @@
 defmodule Omnibot.Plugin do
-  @default_opts [include_base: true, opts: [strategy: :one_for_one]]
+  @default_opts [include_base: true] # strategy: one_for_all
 
   defmodule CfgState do
     use Agent
@@ -16,7 +16,6 @@ defmodule Omnibot.Plugin do
 
     def update_state(pid, fun, timeout \\ 5000) do
       Agent.update(pid, fn {cfg, state} -> {cfg, apply(fun, [state])} end, timeout)
-      #Agent.update(pid, &{&1, apply(fun, [&1])}, timeout)
     end
   end
 

lib/plugin/supervisor.ex

@@ -22,6 +22,6 @@ defmodule Omnibot.Plugin.Supervisor do
   @impl true
   def init({plugin, cfg}) when is_atom(plugin) do
     children = plugin.plugin_children(cfg)
-    Supervisor.init(children, strategy: :one_for_one)
+    Supervisor.init(children, strategy: :one_for_all)
   end
 end