Set up basic CI

.drone.yml

@@ -14,6 +14,7 @@ steps:
     image: docker.io/library/elixir:1.18.3-otp-27
     environment:
       MIX_ENV: test
+      TEST_POSTGRES_HOST: postgres
     commands:
       # Install hex package manager
       - mix local.hex --force

config/test.exs

@@ -8,7 +8,7 @@ import Config
 config :mv, Mv.Repo,
   username: "postgres",
   password: "postgres",
-  hostname: "localhost",
+  hostname: System.get_env("TEST_POSTGRES_HOST", "localhost"),
   database: "mv_test#{System.get_env("MIX_TEST_PARTITION")}",
   pool: Ecto.Adapters.SQL.Sandbox,
   pool_size: System.schedulers_online() * 2