Fix bug accidentally introduced in commit f886c62, remove unnecessary MapSet encoding, efficiency upgrade (avoid encoding unused data structs), version bump to 2.0.0-alpha.3.

Author: darrenklein

README.md

@@ -166,15 +166,15 @@ Install the [Hex](https://hex.pm/packages/ecto_adapters_dynamodb) package by add
 
 ```elixir
 def deps do
-  [{:ecto_adapters_dynamodb, "~> 2.0.0-alpha.2"}]
+  [{:ecto_adapters_dynamodb, "~> 2.0.0-alpha.3"}]
 end
 ```
 
 Otherwise, to fetch from GitHub:
 
 ```elixir
 def deps do
-  [{:ecto_adapters_dynamodb, git: "https://github.com/circles-learning-labs/ecto_adapters_dynamodb", tag: "2.0.0-alpha.2"}]
+  [{:ecto_adapters_dynamodb, git: "https://github.com/circles-learning-labs/ecto_adapters_dynamodb", tag: "2.0.0-alpha.3"}]
 end
 ```
 

lib/ecto_adapters_dynamodb.ex

@@ -252,7 +252,7 @@ defmodule Ecto.Adapters.DynamoDB do
 
     # Ecto migration does not know to specify 'scan: true' to retrieve the persisted migration versions
     # from line 34, file "deps/ecto/lib/ecto/migration/schema_migration.ex"
-    migration_source = Keyword.fetch!(repo.config, :migration_source)
+    migration_source = Keyword.get(repo.config, :migration_source, "schema_migrations")
     updated_opts = if table == migration_source do
       ecto_dynamo_log(:debug, "#{inspect __MODULE__}.execute: table name corresponds with migration source: #{inspect migration_source}. Setting options for recursive scan.", %{})
 

mix.exs

@@ -3,7 +3,7 @@ defmodule Ecto.Adapters.DynamoDB.Mixfile do
 
   def project do
     [app: :ecto_adapters_dynamodb,
-     version: "2.0.0-alpha.2",
+     version: "2.0.0-alpha.3",
      elixir: "~> 1.4",
      build_embedded: Mix.env == :prod,
      start_permanent: Mix.env == :prod,