gethostbyname() fails if socket.gethostname() gives a bad hostname.

[bouthilx]

From @mikepieper

Note: I don't know yet if this is related to #104

The error:

Traceback (most recent call last):
  File "main.py", line 7, in <module>
    from orion.core.io.experiment_builder import ExperimentBuilder
  File "/Users/michaelpieper/anaconda/envs/orion.tutorial/lib/python3.6/site-packages/orion/core/io/experiment_builder.py", line 92, in <module>
    from orion.core.io import resolve_config
  File "/Users/michaelpieper/anaconda/envs/orion.tutorial/lib/python3.6/site-packages/orion/core/io/resolve_config.py", line 71, in <module>
    ('ORION_DB_ADDRESS', 'host', socket.gethostbyname(socket.gethostname()))
socket.gaierror: [Errno 8] nodename nor servname provided, or not known

The hostname:

>>> socket.gethostname()
'Michaels-MBP-2’
>>> socket.gethostbyname(socket.gethostname())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
socket.gaierror: [Errno 8] nodename nor servname provided, or not known

From this stack overflow question (https://stackoverflow.com/questions/39970606/gaierror-errno-8-nodename-nor-servname-provided-or-not-known-with-macos-sie ), I tried:

>>> socket.gethostbyname('localhost')
‘127.0.0.1'

I’m figuring out the best way to resolve that, but just wanted to let you know there might be an issue for Macs.

A solution could be to simply turn the default value to None when gethostbyname() fails.

[bouthilx]

Fixed by #179