Add a high-level API test that initially focuses on various ways that
an Archive object can be directed to use a particular file:

1. filename
2. file-like object opened by name
3. file-like object opened by fileno()

The 3rd way is currently broken for Python 2 and Python 3.

Instead of using an external utility (/usr/bin/zip) and a subprocess
call, use Python's own zipfile module to create temporary zip file.

Currently, unit testing does not cleanup the temporary directory
structure that it creates. Make it more easily identifiable for manual
cleanup by adding a recognizable suffix.

Check if data is already bytes

Python 3

This reverts commit a2fe91f8cf.

This reverts commit bf44649ce8.

Added unittest for writing directories.

Add option to set mode to folder.

Fixed installation of packages via pip