Install fails bc of configuation requirements

[abelsonlive]

If I install askmanta without first configuring environmental variables, it gives me this error:

  Running setup.py (path:/var/folders/4m/zzbwyss11r77z85h92r63lcr0000gn/T/pip-VuyTdS-build/setup.py) egg_info for package from git+https://github.com/stdbrouw/askmanta
    Traceback (most recent call last):
      File "<string>", line 17, in <module>
      File "/var/folders/4m/zzbwyss11r77z85h92r63lcr0000gn/T/pip-VuyTdS-build/setup.py", line 3, in <module>
        from askmanta import VERSION
      File "askmanta/__init__.py", line 5, in <module>
        import job, manifest
      File "askmanta/job.py", line 5, in <module>
        from askmanta.environment import client
      File "askmanta/environment.py", line 9, in <module>
        if 'localhost' in os.environ['MANTA_URL']:
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/UserDict.py", line 23, in __getitem__
        raise KeyError(key)
    KeyError: 'MANTA_URL'

This should be somehow covered on initialization of jobs etc or more explicitly stated.

i wrote a connect module but wasn't sure how to integrate it, hence no PR ;).

import os
import logging
import manta 

logging.basicConfig()

MANTA_URL = os.getenv('MANTA_URL')
MANTA_USER = os.getenv('MANTA_URL')
MANTA_KEY_ID = os.getenv('MANTA_KEY_ID')

class MantaConnectionError(Exception):
  pass

def _check_env():
  """
  Make sure environmental variables are present.
  """
  if not MANTA_URL:
    raise MantaConnectionError(
      'You must set MANTA_URL as an environmental variable.'
    )

  if not MANTA_USER:
    raise MantaConnectionError(
      'You must set MANTA_USER as an environmental variable.'
    )

  if 'localhost' not in MANTA_URL:
    if not MANTA_KEY_ID:
      raise MantaConnectionError(
        'For a non-local client, you must set'
        'MANTA_KEY_ID as an environmental variable.'
      )  

def connect():
  """
  connect to manta 
  """
  _check_env()

  if 'localhost' in MANTA_URL:
    client = manta.MantaClient(MANTA_URL, MANTA_USER, internal=True)
  else:
    signer = manta.SSHAgentSigner(MANTA_KEY_ID)
    client = manta.MantaClient(MANTA_URL, MANTA_USER, MANTA_KEY_ID)

  return client

# HACK for now, should figure out how 
# to announce errors on init of various classes.
client = connect()