Display message while uploading and removing assets
Display message while uploading and removing assets

This commit creates a method, `show_during`, which shows a message
before doing a thing, does the thing, then prints carriage returns to
hide the message.

kewaunited/shopify_theme,tyler-king/shopify_theme,micdijkstra/shopify_theme_tool,jeffrafter/shopify_theme,jdlich/shopify_theme,Shopify/shopify_theme,rickysalsberry/shopify_theme