Initial working accurate load test

accurate_config.py contains all of the configs accurate.py.

When the start button is pushed, a period of time is spent gathering
data from your Designate environment for getting/deleting zones and
records.

An accurate test requires a set of tenants with particular numbers of
zones. There are two types of tenants: large and small, where a large
tenant has more domains than a small domain. The test requires two
different kinds of users, a large user and a small user, which have the
same set of tasks but different task weights.

Redis integration for API-BIND propagation time is functional. There
is a flag to enable/disable sending data to Redis. There is one
relatively minor problem with Redis integration: whenever zone changes
occur via recordset operations, we have to do an additional GET to
retrieve the serial number for the zone. The task weights in the config
file don't take these additional requests into account, so you'll see
some additional GET /zones/zoneID requests when using Redis.

prepare_test.py creates domains and records for a specified number of
tenants and spits out files with the test data. It currently needs some
additional cli options to specify the number of large and small users,
and it needs to be converted into a locust file so test preparation
can happen much faster (do requests in parallel)