Add recursive dns option and reenable test

Author: ianopolous

src/main/java/io/ipfs/api/IPFS.java

@@ -134,8 +134,8 @@ public Map resolve(String scheme, Multihash hash, boolean recursive) throws IOEx
     }
 
 
-    public String dns(String domain) throws IOException {
-        Map res = retrieveMap("dns?arg=" + domain);
+    public String dns(String domain, boolean recursive) throws IOException {
+        Map res = retrieveMap("dns?arg=" + domain + "&r=" + recursive);
         return (String)res.get("Path");
     }
 

src/test/java/io/ipfs/api/APITest.java

@@ -618,10 +618,9 @@ public void nameTest() throws IOException {
     }
 
     @Test
-    @Ignore("[#103] DNS test cannot resolve name")
     public void dnsTest() throws IOException {
         String domain = "ipfs.io";
-        String dns = ipfs.dns(domain);
+        String dns = ipfs.dns(domain, true);
     }
 
     public void mountTest() throws IOException {