Ported Flow to XS

xs/t/16_flow.t

@@ -0,0 +1,29 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Slic3r::XS;
+use Test::More tests => 2;
+
+{
+    my $flow = Slic3r::Flow->new_from_width(
+        role => Slic3r::Flow::FLOW_ROLE_PERIMETER,
+        width               => '1',
+        nozzle_diameter     => 0.5,
+        layer_height        => 0.3, 
+        bridge_flow_ratio   => 1,
+    );
+    isa_ok $flow, 'Slic3r::Flow', 'new_from_width';
+}
+
+{
+    my $flow = Slic3r::Flow->new(
+        width               => 1,
+        spacing             => 0.95,
+        nozzle_diameter     => 0.5,
+    );
+    isa_ok $flow, 'Slic3r::Flow', 'new';
+}
+
+__END__