Merge pull request maccman#5 from airbnb/switch-to-text-column

Change url field to TEXT because urls can be long

Author: Allen Kerr

migrations/002_change_url_to_text.rb

@@ -0,0 +1,13 @@
+Sequel.migration do
+  up do
+    alter_table :links do
+      set_column_type :url, Text
+    end
+  end
+
+  down do
+    alter_table :links do
+      set_column_type :url, String
+    end
+  end
+end