Cloudify Cosmo Wagon Versions Save

• Fix get_source(..) case where it extracts the archive but doesn't delete it on failure

• Drop support for Python 2.6 and Python 3.3 (as per Wheel's official support since 0.30.0)
• Fix #112

Wheel>0.30.0 dropped support for Python 2.6, 3.2 and 3.3. To use Wagon with any of these versions of Python, Wagon 0.6.1 should be used.

Previously, Wagon would use the Python, pip and wheel executables that were in the path, or, if using a virtualenv, those within it. That is, you couldn't use another python that's not in the path. That's now fixed as we're now using the python, pip and wheel relative to the sys.executable path.

• Added a --format flag allowing to also choose the zip format for the wagon. Default is tar.gz.
• Wagons now have the .wgn extension.
• It is no longer required to provide a package_name==package_version when creating from PyPI. using wagon create -s flask will create a wagon of the latest version of Flask found in PyPI.
• Arbitrary pip args can be passed to the create and install commands via the -a flag. e.g. wagon create -s flask -a '--retries 5'.
• To pack up internal requirement files, you can now simply provide the -r flag instead of -r . which will look for requirement files within the path/archive. To explicitly provide additional requirement files, you can use the additional pip args feature.

• Wagon now officially supports Windows (and is tested via AppVeyor)
• { platform } tag is now generated using wheel's implementation for consistency's sake.

• You can now pass arbitrary pip args to wagon create via the wheel-args flag.
• You can now pass arbitrary pip args to wagon install via the install-args flag.

Attempting to install a package's dependencies from a dev-requirements file by using the -r flag failed. It has been fixed.

• The default logger will no longer override the user's logger when importing wagon.
• Module -> Package (everywhere). Most importantly, the metadata now include package_name and package_version instead of module_name and module_version (what the hell was I thinking?).