Addressed as part of https://github.com/netty/netty/pull/3217

HTTP/2 HPACK 10
[HPACK 10](https://tools.ietf.org/html/draft-ietf-httpbis-header-compression-10) has been released.  We should update our [twitter hpack](https://github.com/twitter/hpack) dependencies.

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2CodecUtil.java
codec-http2/src/main/java/io/netty/handler/codec/http2/Http2CodecUtil.java
diff --git a/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2CodecUtil.java b/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2CodecUtil.java
index 3b0be13d598..b38aee2d6dd 100644
--- a/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2CodecUtil.java
+++ b/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2CodecUtil.java
@@ -34,8 +34,9 @@ public final class Http2CodecUtil {
     public static final int CONNECTION_STREAM_ID = 0;
     public static final int HTTP_UPGRADE_STREAM_ID = 1;
     public static final String HTTP_UPGRADE_SETTINGS_HEADER = "HTTP2-Settings";
-    public static final String HTTP_UPGRADE_PROTOCOL_NAME = "h2c-16";
-    public static final String TLS_UPGRADE_PROTOCOL_NAME = "h2-16";
+    // Draft 14 is the latest "implementation draft" as defined by https://http2.github.io/
+    public static final String HTTP_UPGRADE_PROTOCOL_NAME = "h2c-14";
+    public static final String TLS_UPGRADE_PROTOCOL_NAME = "h2-14";
 
     public static final int PING_FRAME_PAYLOAD_LENGTH = 8;
     public static final short MAX_UNSIGNED_BYTE = 0xFF;
