Update for changes to Hy

[cookyzed]

This is the error:

$ hy conway.hy
Traceback (most recent call last):
  File "C:\Users\cz\AppData\Local\Programs\Python\Python37-32\Scripts\hy-script.py", line 12, in <module>
    sys.exit(hy_main())
  File "c:\users\cz\appdata\local\programs\python\python37-32\lib\site-packages\hy\cmdline.py", line 388, in hy_main
    sys.exit(cmdline_handler("hy", sys.argv))
  File "c:\users\cz\appdata\local\programs\python\python37-32\lib\site-packages\hy\cmdline.py", line 374, in cmdline_handler
    runhy.run_path(filename, run_name='__main__')
  File "c:\users\cz\appdata\local\programs\python\python37-32\lib\runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "c:\users\cz\appdata\local\programs\python\python37-32\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "c:\users\cz\appdata\local\programs\python\python37-32\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "D:\git\hyway\conway.hy", line 3, in <module>
    (def *world* (grid.Torus 10 10))
NameError: name 'hyx_def' is not defined

$ hy --version
hy 0.15.0+67.ga5ed98f

$ python --version
Python 3.7.2