Add punycode support

Fixes #8

Gopkg.lock

@@ -7,9 +7,36 @@
   packages = ["."]
   revision = "500bd5b9081b5957ac10389f86e069869f00c348"
 
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/net"
+  packages = ["idna"]
+  revision = "e514e69ffb8bc3c76a71ae40de0118d794855992"
+
+[[projects]]
+  name = "golang.org/x/text"
+  packages = [
+    "collate",
+    "collate/build",
+    "internal/colltab",
+    "internal/gen",
+    "internal/tag",
+    "internal/triegen",
+    "internal/ucd",
+    "language",
+    "secure/bidirule",
+    "transform",
+    "unicode/bidi",
+    "unicode/cldr",
+    "unicode/norm",
+    "unicode/rangetable"
+  ]
+  revision = "f21a4dfb5e38f5895301dc265a8def02365cc3d0"
+  version = "v0.3.0"
+
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "b3ca26cded7865674be15028cfaf931f68a028db1f3c1588b9d0ae96e41cfbd8"
+  inputs-digest = "eb8c5336b6da0643bb04cf921e8e61c2966555c879bc20533b060724d71667c6"
   solver-name = "gps-cdcl"
   solver-version = 1