Add support for marking conversation as read (#234)

Author: thewheat

README.md

@@ -584,6 +584,9 @@ userReply.setBody("Mighty fine shindig");
 userReply.setAttachmentUrls(new String[]{"http://www.example.com/attachment.jpg"}); // optional - list of attachments
 System.out.println(MapperSupport.objectMapper().writeValueAsString(userReply));
 Conversation.reply("66", userReply);
+
+// mark conversation as read
+Conversation.markAsRead("66");
 ```
 
 ### Webhooks

intercom-java/src/main/java/io/intercom/api/Conversation.java

@@ -17,6 +17,18 @@
 @JsonIgnoreProperties(ignoreUnknown = true)
 public class Conversation extends TypedData {
 
+    @SuppressWarnings("UnusedDeclaration")
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    private static class ConversationRead extends TypedData {
+
+        @JsonProperty("read")
+        private boolean read;
+
+        public ConversationRead() {
+            this.read = true;
+        }
+    }
+
     private static final HashMap<String, String> SENTINEL = Maps.newHashMap();
     private static final List<String> DISPLAY_AS_FORMATS = Lists.newArrayList("plaintext", "html");
     static final String MESSAGE_TYPE_ASSIGNMENT = "assignment";
@@ -73,6 +85,16 @@ public static Conversation reply(String id, AdminReply reply) {
             .post(Conversation.class, new AdminReply.AdminStringReply(reply));
     }
 
+    public static Conversation markAsRead(String id) {
+        final URI uri = UriBuilder.newBuilder()
+                .path("conversations")
+                .path(id)
+                .build();
+
+        return new HttpClient(uri)
+                .put(Conversation.class, new ConversationRead());
+    }
+
     public static UserMessage create(UserMessage message) {
         return DataResource.create(message, "messages", UserMessage.class);
     }