[Test] Use now full qualified names for fields

We were asking for short name fields but elasticsearch does not allow anymore using short names but full qualified names.

```java
SearchResponse response = client().prepareSearch("test")
        .addField("content_type")
        .addField("name")
        .execute().get();
```

We need to use now:

```java
SearchResponse response = client().prepareSearch("test")
        .addField("file.content_type")
        .addField("file.name")
        .execute().get();
```

Closes #102.

README.md

@@ -299,12 +299,12 @@ GET /test/person/_search
   "fields": [], 
   "query": {
     "match": {
-      "file": "king queen"
+      "file.file": "king queen"
     }
   },
   "highlight": {
     "fields": {
-      "file": {
+      "file.file": {
       }
     }
   }
@@ -332,7 +332,7 @@ It gives back:
             "_id": "1",
             "_score": 0.13561106,
             "highlight": {
-               "file": [
+               "file.file": [
                   "\"God Save the <em>Queen</em>\" (alternatively \"God Save the <em>King</em>\"\n"
                ]
             }

src/test/java/org/elasticsearch/plugin/mapper/attachments/test/SimpleAttachmentIntegrationTests.java

@@ -141,8 +141,8 @@ public class SimpleAttachmentIntegrationTests extends ElasticsearchIntegrationTe
         refresh();
 
         SearchResponse response = client().prepareSearch("test")
-                .addField("content_type")
-                .addField("name")
+                .addField("file.content_type")
+                .addField("file.name")
                 .execute().get();
         String contentType = response.getHits().getAt(0).getFields().get("file.content_type").getValue();
         String name = response.getHits().getAt(0).getFields().get("file.name").getValue();