[dashboard] too loose regex for murano/categories/add url

[Lin Yang]

How to reproduce:
Input a mistake url http://{horizon}/murano/categories/addabcd into browser, it shows the view of adding category instead of 404 as expect.

Root cause:
The current url regex '^add' is too loose, which will match all url start with 'add'.
https://git.openstack.org/cgit/openstack/murano-dashboard/tree/muranodashboard/categories/urls.py#n24

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/204486

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/204486
Committed: https://git.openstack.org/cgit/openstack/murano-dashboard/commit/?id=a98d91cb5d10df5224108a005320b265d9fb6a76
Submitter: Jenkins
Branch: master

commit a98d91cb5d10df5224108a005320b265d9fb6a76
Author: Lin Yang <email address hidden>
Date: Wed Jul 22 16:12:27 2015 +0800

    Fix too loose url regex for murano/categories/add

    Current url regex '^add' will match all urls start with 'add' by mistake. The
    '$' added will make sure the regex only match 'add' as expect.

    Change-Id: I0611cbe76b6614f7aa694124767c6caaccfb5890
    Closes-Bug: #1476991