reduce bcrypt complexity in test increase speed

When FactoryGirl (or any similar method of creating users in a test environment)
creates a user, bcrypt creates a secure password hash, which is pointless for
a test environment and can *really* slow things down.

Of course, having a slow bcrypt in production is critical, as it is in part the
slowness of hash functions that make them secure.

Using the minimum bcrypt complexity in the test environment allows test users
to be created much faster, speeding up the test process.