Comment 2 for bug 1567697

In 16.04 beta you only need to have the package libnghttp2-dev as a build-dep, download the ubuntu package source, recompile and installed the newly created package.

$ sudo apt-get build-dep curl
$ sudo apt-get install libnghttp2-dev
$ sudo apt-get source curl
$ sudo debian/rules binary
$ sudo dpkg -i *deb
(actually, you can only install the nss, gnutls or openssl version of the lib package. Let's go with openssl here)

$ curl --http2 -I nghttp2.org
HTTP/1.1 101 Switching Protocols
Connection: Upgrade
Upgrade: h2c

HTTP/2.0 200
date:Fri, 08 Apr 2016 22:19:10 GMT
content-type:text/html
content-length:6646
last-modified:Sun, 03 Apr 2016 06:53:14 GMT
etag:"5700bdda-19f6"
link:</stylesheets/screen.css>; rel=preload; as=stylesheet
accept-ranges:bytes
x-backend-header-rtt:0.00102
server:nghttpx nghttp2/1.10.0-DEV
via:2 nghttpx
x-frame-options:SAMEORIGIN
x-xss-protection:1; mode=block
x-content-type-options:nosniff