Bump django-compressor to 1.5
Bump django-compressor to 1.5

django-compressor 1.4 does not support well Django 1.8,
and the `manage.py compress` was failing with
`ImportError: cannot import name template_source_loaders`

We cannot go above 1.5, as starting with 1.6, the unit test
`test_query` in `test_urlprefix.URLPrefixTestCase` fails with
'''
UncompressableFileError: '/test/static/bootstrap/css/bootstrap.css'
isn't accessible via COMPRESS_URL ('/static/') and can't be compressed
'''

maks-us/cabot,maks-us/cabot,maks-us/cabot,arachnys/cabot,maks-us/cabot,arachnys/cabot,arachnys/cabot,arachnys/cabot