Reorder static handlers
Change version to development

This means that deployments from the develop branch should go to the
development version by default. Version should be changed to production
when releasing.
Remove unnecessary entry from skip_files
Moved to using github.com/disintegration/imaging instead of image/draw.
Further refined our caching
Added version constant to siggen/util
Changed deployment version to production
Merge branch 'release/0.8.0'

Conflicts:
	app.yaml