Add support for travis CI

[karenc]

python-zope.interface was installed in aptitude, and it was an old version that doesn't have registry. Removing it fixes the tests.

Skip cnxpublishing.tests in configurator scan

To fix the following error:

      File "/home/karen/cnx-publishing/cnxpublishing/main.py", line 31, in main
        config.scan()
      File "/usr/local/lib/python2.7/dist-packages/pyramid-1.4.4-py2.7.egg/pyramid/config/__init__.py", line 947, in scan
        ignore=ignore)
      File "/usr/local/lib/python2.7/dist-packages/venusian-1.0a8-py2.7.egg/venusian/__init__.py", line 199, in scan
        __import__(modname)
      File "/home/karen/cnx-publishing/cnxpublishing/tests/test_publish.py", line 16, in <module>
        import mock
    ImportError: No module named mock

[mmulich]

Looks fine, except the PasteDeploy dependency declaration is not necessary.
Needs rebased.

[karenc]

Removed PasteDeploy from setup.py