Extract some options from build script into constants.
Extract some options from build script into constants.

modulexcite/text-app,modulexcite/text-app,zkendall/WordBinder,zkendall/WordBinder,l3dlp/text-app,l3dlp/text-app,modulexcite/text-app,zkendall/WordBinder,l3dlp/text-app,codex8/text-app,wearefractal/extension-boiler,codex8/text-app,codex8/text-app