Status constants are replaced by the Status class of Enum type.
Commented data files in setup.py.
An unreachable host is no longer an error.

The ResourceUnavailableException class subclasses RuntimeError. If it is
not possible to ssh into the sourcehost, this exception is raised, a
message is logged at INFO level and the program moves on to the next
host.

Other changes:
  The __init__.py module was cleaned up.
  FlaggedSnapshotError was moved from cycle to __init__.
  The 'ssh' and 'sourcehost' keys were added to the DEFAULT dict.
  Unit tests were adjusted.
  A behave feature scenario was created.
Version 1.0.1