create session does not tell on which beacon

as the problem occurred for @vergaral we might have to think about the following:

if you create a new session with

$ bliss --create myNewSession

without explicitly declaring BEACON_HOST your new session might be created anywhere and you don't even know where...

the minimum to do would be to at the print to the output stating the beacon server where it is created. However, I guess there are also other options to consider.

current output:

$  bliss --create myNewSession
Creating 'myNewSession' BLISS session 
Creating sessions/myNewSession.yml
Creating sessions/myNewSession_setup.py
Creating sessions/scripts/myNewSession.py

proposed output:

$  bliss --create myNewSession
Creating 'myNewSession' BLISS session on localhost
Creating sessions/myNewSession.yml
Creating sessions/myNewSession_setup.py
Creating sessions/scripts/myNewSession.py