How to install openstack in Ubuntu 14.04?

I would like to install Openstack Havana in my system(14.04).

I have tried this link. I haveclone` devstack by,

sudo git clone https://github.com/openstack-dev/devstack.git -b stable/havana

I can saw in folder devstack,

arul@arul-PC:~/openstack/devstack$ ls
AUTHORS   exerciserc   extras.d   HACKING.rst  openrc           run_tests.sh  stack.sh  unstack.sh
clean.sh  exercises    files      lib          README.md        samples       tests

eucarc exercise.sh functions LICENSE rejoin-stack.sh stackrc tools

When I try,

arul@arul-PC:~/openstack/devstack$ ./stack.sh

I got response as,

WARNING: this script has not been tested on trusty
[Call Trace]
./stack.sh:137:die
[ERROR] ./stack.sh:137 If you wish to run this script anyway run with FORCE=yes

Where I can get 'openstack' tested with trusty?

---

EDIT

When I tried to install icehouse using,

arul@arul-PC:~$ sudo add-apt-repository cloud-archive:icehouse

I got response as,

Ubuntu Cloud Archive for Openstack icehouse
More info: https://wiki.ubuntu.com/ServerTeam/CloudArchive
Press [ENTER] to continue or ctrl-c to cancel adding it
cloud-archive only supported on precise