Add types to some new arguments

Because if you don't, they default to strings and that's not good.

$ sbws generate -n 1
[... snip ...]
Traceback (most recent call last):
  File "/home/matt/src/simple-bw-scanner/venv-editable/bin/sbws", line 11, in <module>
    load_entry_point('sbws', 'console_scripts', 'sbws')()
  File "/home/matt/src/simple-bw-scanner/sbws/sbws.py", line 75, in main
    exit(comm['f'](*comm['a'], **comm['kw']))
  File "/home/matt/src/simple-bw-scanner/sbws/core/generate.py", line 99, in main
    min_num=args.min_num)
  File "/home/matt/src/simple-bw-scanner/sbws/lib/v3bwfile.py", line 474, in from_results
    min_num)
  File "/home/matt/src/simple-bw-scanner/sbws/lib/v3bwfile.py", line 279, in from_results
    min_num)
  File "/home/matt/src/simple-bw-scanner/sbws/lib/v3bwfile.py", line 326, in min_num_results
    if len(results) > min_num:
TypeError: unorderable types: int() > str()

-p, -a, and -n all need a type I bet.