Incorrect handling of connection errors

[samueldg]

Looks like connection error handler code throws an exception (at least in this version of the Redis client):

Traceback (most recent call last):
  File ".../snappass/venv/bin/snappass", line 9, in <module>
    load_entry_point('snappass', 'console_scripts', 'snappass')()
  File ".../snappass/snappass/main.py", line 40, in inner
    print('Failed to connect to redis! %s' % e.message)
AttributeError: 'ConnectionError' object has no attribute 'message'

And double-checking:

>>> from redis.exceptions import ConnectionError
>>> 'message' in dir(ConnectionError)
False

Using str(e) probably solves the issue, and I guess adding a test would make sense.

Relates to the changes in #24

[aadarsh-nagrath]

It seems error indicates that an AttributeError is raised because the 'ConnectionError' object has no 'message' attribute. So I think using str(e) instead of e.message is reasonable, as str(e) will convert the exception object to a string and include the error message.