use the SHA1 mangler when initializing the cache
    
    This will coerces keys into a SHA1 hash so that we can store them into
    memcached.
    
    For example, a key like "greenwave.resources:retrieve_results|{u'item': u'glibc-1.0-1.el7', u'type': u'koji_build'}"
    will be coerced to "ff9de47a58ea967111b36a5c8a94eab51c4bc4ef".