some compiler warnings removed

lib/mix/tasks/papertrail/install.ex

@@ -1,12 +1,12 @@
 defmodule Mix.Tasks.Papertrail.Install do
   @shortdoc "generates paper_trail migration file for your database"
 
-  import Macro, only: [camelize: 1, underscore: 1]
+  import Macro, only: [underscore: 1]
   import Mix.Generator
 
   use Mix.Task
 
-  def run(args) do
+  def run(_args) do
     path = Path.relative_to("priv/repo/migrations", Mix.Project.app_path)
     file = Path.join(path, "#{timestamp()}_#{underscore(AddVersions)}.exs")
     create_directory path

lib/paper_trail.ex

@@ -1,7 +1,6 @@
 defmodule PaperTrail do
-  import Ecto.Query
   import PaperTrail.VersionQueries
-  
+
   alias Ecto.Multi
   alias PaperTrail.Version
 
@@ -24,7 +23,7 @@ defmodule PaperTrail do
   def update(changeset, meta \\ nil) do
     Multi.new
     |> Multi.update(:model, changeset)
-    |> Multi.run(:version, fn %{model: model} ->
+    |> Multi.run(:version, fn %{model: _model} ->
         version = make_version_struct(%{event: "update"}, changeset, meta)
         Repo.insert(version)
       end)

lib/version.ex

@@ -1,9 +1,7 @@
 defmodule PaperTrail.Version do
   use Ecto.Schema
 
-  import Ecto
   import Ecto.Changeset
-  import Ecto.Query
 
   schema "versions" do
     field :event, :string

test/test_helper.exs

@@ -63,4 +63,5 @@ end
 Repo.start_link
 
 ExUnit.configure seed: 0
+
 ExUnit.start()