Added some test level changes
Updated level format, added saving support
Levels now have a "default constructor"
Added grid of periods
Fixed level export bug
Level import/export in editor
Ignore Python build artifacts
Properly handle iteration and assignment of tiles
Fully functional
Save/Load title/text
Added "change start fuel"
Added start/end position selectors
Added info box listing fuel, start, end
Merge pull request #23 from liam-middlebrook/levels/editor

lgtm :thumbsup: