Improve metadata storage (#37)

* Updated config path to specify metadata storage path

* Removed metadata column from DB, replacing it with filepath columns

* Updated app to store compressed metadata; automatically download thumbnails

* Ensured metadata is deleted when other files are deleted

* Updated docs

* Added inets to application start so http calls work in prod

lib/pinchflat/http/http_behaviour.ex

@@ -0,0 +1,8 @@
+defmodule Pinchflat.HTTP.HTTPBehaviour do
+  @moduledoc """
+  This module defines the behaviour for HTTP clients. Literally just
+  so I can use Mox to create an HTTP mock
+  """
+
+  @callback get(String.t(), Keyword.t(), Keyword.t()) :: {:ok, String.t()} | {:error, String.t()}
+end

lib/pinchflat/http/http_client.ex

@@ -0,0 +1,35 @@
+defmodule Pinchflat.HTTP.HTTPClient do
+  @moduledoc """
+  This module provides a simple interface for making HTTP requests.
+
+  Made to be easily swappable with other HTTP clients. If you need more complexity
+  or security, check out HTTPoison or Mint.
+  """
+
+  alias Pinchflat.HTTP.HTTPBehaviour
+
+  @behaviour HTTPBehaviour
+
+  @doc """
+  Makes a GET request to the given URL and returns the response.
+
+  NOTE: I can't really test this with Mox and I can't think of a way to test this
+  that isn't ultimately redundant. I'm just going to leave it untested for now and
+  focus more on testing the consumers of this module.
+
+  Returns {:ok, String.t()} | {:error, String.t()}
+  """
+  @impl HTTPBehaviour
+  def get(url, headers \\ [], opts \\ []) do
+    case :httpc.request(:get, {url, headers}, [], opts) do
+      {:ok, {{_version, 200, _reason_phrase}, _headers, body}} ->
+        {:ok, body}
+
+      {:ok, {{_version, status_code, reason_phrase}, _headers, _body}} ->
+        {:error, "HTTP request failed with status code #{status_code}: #{reason_phrase}"}
+
+      {:error, reason} ->
+        {:error, "HTTP request failed: #{reason}"}
+    end
+  end
+end