New py5 Release: 0.6.0.alpha.2

A big release with new features and important bug fixes!

What's new:

• Context Managers. This context manager functionality is one of many great ideas found in processing.py that several members of the py5 community have been asking for. Ideas and feedback like this contribute much to py5, so please keep them coming! And many thanks to the processing.py team for coming up with this idea.
• py5bot now supports the SVG and PDF renderers
• Update to the latest Processing 4.0 beta 2 jars
• The save() and save_frame() methods can now save to a io.BytesIO object
• Version number now conforms to proper semantic versioning standards

Bug Fixes:

• #40
• #44
• Other small bugs I found and fixed along the way

What's Ahead:

• Rework noise functionality. See #38 for more information. The new version's noise functionality may not be backwards compatible.
• There are other items on my todo list but I want to make reworking the noise functionality a higher priority. I'll do a new release once this is complete.