Create output folder if missing
Move filsystem function to a package
Merge branch 'master' into create-output-directory-if-missing

Conflicts:
	create_pages.py
Generate High-Volume Transactions page
Filter high volume transactions only once
Extract method to render template
Fix style warnings
Add link property to service class
Remove author notice and add newline at end of file
Introducing Quarter class
Highlight total cost if not latest quarter
Highlight all cells
Format template
Move test support functions to __init__.py
Render empty cells for None values
Highlight correct navigation entry
Rename to high-volume-services
Use the same var to set current navigation link
Implement total ordering for Quarters
Detect latest quarter from data