Allow for fully native builds too

Skipping multiarch if there's a platform match between dev and prod.

test/builder_command_test.rb

@@ -0,0 +1,24 @@
+require "test_helper"
+require "mrsk/configuration"
+require "mrsk/commands/builder"
+
+class BuilderCommandTest < ActiveSupport::TestCase
+  setup do
+    @config = { service: "app", image: "dhh/app", registry: { "username" => "dhh", "password" => "secret" }, servers: [ "1.1.1.1" ] }
+  end
+
+  test "target multiarch by default" do
+    builder = Mrsk::Commands::Builder.new(Mrsk::Configuration.new(@config))
+    assert builder.multiarch?
+  end
+
+  test "target native when multiarch is off" do
+    builder = Mrsk::Commands::Builder.new(Mrsk::Configuration.new(@config.merge({ builder: { "multiarch" => false } })))
+    assert builder.native?
+  end
+
+  test "target multiarch remote when local and remote is set" do
+    builder = Mrsk::Commands::Builder.new(Mrsk::Configuration.new(@config.merge({ builder: { "local" => { }, "remote" => { } } })))
+    assert builder.remote?
+  end
+end