Enable pexpect and redis by default on setuptools

[piraz]

Redis and pexpect should be added by default, disabling will be made by using optional parameters.

The sqlalchemy and schedule(croniter) optionals will remain as is.

With that change if you want just add schedule to the redis and pexpect:

pip install firenado[schedule]

Maybe you want an agent with scheduled features and no redis:

pip install firenado[schedule noredis]

Or don't need ProcessLaucher but sqlalchemy support:

pip install firenado[sqlalchemy nopexpect]