How to install Livestreamer --- super n00b terminal question
The # is usually used in shell command samples to show the shell prompt and should not be entered. As it is also the comment indicator, the command you've entered just does nothing.

Make sure you are logged into an account with Administrator privileges to run the command. Then run

easy_install -U livestreamer


or (only if the above gives you "access denied" errors)

sudo easy_install -U livestreamer