Bug fix for PykeException

Fixed a bug where PykeExceptions was not being constructed properly.
Removed unneeded files.

Removed the files that are no longer needed due to the refactor. Started
using find_packages in the setup script rather than manually specifying
files. Fixed a bug in the build method for Target where it would throw
an error when trying to run a dpendency.
Refactored the command line functionality

Moved it into it's own module cli, leaving the __init__ file for pyke to
contain only imports, meta data and some common functionality.
Updated the change log.