Add alternative download location

[smcabrera]

Currently the downloaded videos will download to the current directory, wherever you are when you run the command. This can be inconvenient though, as more than once I have downloaded a video only to realize that I've done so in the project I'm currently working on...and just checked it into git. Oops!

It would be nice for there to be an option for a default location other than the current directory that could perhaps be specified in a .get_freaky type config file, or perhaps an ENV variable. You could run a command like:

get_freaky config --dir ~/Movies

And videos would instead default to downloading to your movies directory rather than the current directory. I suppose it would also be nice to add a feature that would allow you to specify the directory on the fly through a flag, but that's a separate issue.