Refs #17. Adding logger to top-level script.
Refs #17. Adding logger to MoonInfo class.
Refs #17. Code cleanup in top-level script.
Refs #17. Fixing formatting for MoonInfo logging.
Refs #17. Changing main logging format ordering.
Refs #17. Add executable line to make things easier.
Refs #17. Adding logging for ObservingSite.
Refs #17. Add error handling for log file writing.
Merge pull request #29 from mareuter/17_add_logger

17 add logger