Added kind of dynamic makefile target
Added kind of dynamic makefile target

With this modification you can run:
"make cmd=shell"
or
"make cmd=makemigrations"
as very similar cmds.
Another case would be runserver because this command needs a port.

With this change the hard coded targets like "shell", "migrate" and "runserver"
would be obsolete.

issue #8

transcode-de/cookiecutter-django-project,transcode-de/cookiecutter-django-project,transcode-de/cookiecutter-django-project,transcode-de/cookiecutter-django-project