refactors utils

Author: jscott22

lib/utils.ex

@@ -1,23 +1,27 @@
 defmodule Bigtable.Utils do
   @moduledoc false
 
+  @spec configured_table_name() :: binary()
   def configured_table_name do
     instance = configured_instance_name()
     table = Application.get_env(:bigtable, :table)
 
     "#{instance}/tables/#{table}"
   end
 
+  @spec configured_instance_name() :: binary()
   def configured_instance_name do
     project = get_project()
     instance = get_instance()
     "projects/#{project}/instances/#{instance}"
   end
 
+  @spec get_project() :: binary()
   defp get_project do
     Application.get_env(:bigtable, :project)
   end
 
+  @spec get_instance() :: binary()
   defp get_instance do
     Application.get_env(:bigtable, :instance)
   end