refactor, remove unnecessary dependencies, speed up instance check query

README.md

@@ -56,8 +56,6 @@ Farside's routing is very minimal, with only the following routes:
 
 - `/`
   - The app home page, displaying all live instances for every service
-- `/ping`
-  - A passthrough "ping" to redis to ensure both app and redis are working
 - `/:service/*glob`
   - The main endpoint for redirecting a user to a working instance of a
     particular service with the specified path
@@ -108,12 +106,9 @@ that their mission to centralize the entire web behind their service ultimately
 goes against what Farside is trying to solve. Use at your own discretion.
 
 ## Development
-- Install [redis](https://redis.io)
 - Install [elixir](https://elixir-lang.org/install.html)
 - (on Debian systems) Install [erlang-dev](https://https://packages.debian.org/sid/erlang-dev)
-- Start redis: `redis-server`
 - Install dependencies: `mix deps.get`
-- Initialize redis contents: `mix run -e Farside.Instances.sync`
 - Run Farside: `mix run --no-halt`
   - Uses localhost:4001
 
@@ -123,5 +118,4 @@ goes against what Farside is trying to solve. Use at your own discretion.
 | -- | -- |
 | FARSIDE_TEST | If enabled, bypasses the instance availability check and adds all instances to the pool. |
 | FARSIDE_PORT | The port to run Farside on (default: `4001`) |
-| FARSIDE_REDIS_PORT | The Redis server port to use (default: `6379`, same as the default for Redis) |
 | FARSIDE_SERVICES_JSON | The "services" JSON file to use for selecting instances (default: `services.json`) |