Avoid ImportError on selenium

[Sascha Peilicke]

Several distribution can't ship selenium due to it's non-free license. So they have to patch it out of test-requirements.txt. Instead of having to also patch out all selenium-related tests, it's easier to improve WITH_SELENIUM by avoiding an import failure and force not running selenium tests.

[Sascha Peilicke (saschpe)]

Selenium isn't part of most OSS distributions because it ships binaries which can't be easily built from source. Here are some reference bugs:

openSUSE:
https://bugzilla.novell.com/show_bug.cgi?id=755619

Debian:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=636677
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=700061

[Julie Pichon (jpichon)]

Thanks for the summary Sascha.

Link to the mailing list discussion: http://lists.openstack.org/pipermail/openstack-dev/2013-July/011377.html

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/35649
Committed: http://github.com/openstack/horizon/commit/19d62d56172374571fccfe3f1dbb5f052c14ce35
Submitter: Jenkins
Branch: master

commit 19d62d56172374571fccfe3f1dbb5f052c14ce35
Author: Sascha Peilicke <email address hidden>
Date: Thu Jul 4 15:18:21 2013 +0200

    Avoid ImportError when selenium is missing.

    Also provide a warning message. Fixes LP bug 1197815

    Change-Id: Id7ffaa8820eefd216d2258d56736a65ddb2483c2