mix.exs:
```elixir
def application do
[
applications: [:logger, :logger_file_backend, ...],
mod: {Snippets, []}
]
end
def deps do
[
{:cowboy, "~> 1.0.0"}, # web server
{:logger_file_backend, "~> 0.0.7"} # writes log messages to a file, LOL
....
]
end
```
config/dev.exs:
```elixir
config :logger, :error_log,
path: "log/app.log",
level: :debug
```