Deleting Shell_CheatSheet.md and Shell_ouline.md from master SWC boot-camps repository
Adding SQL cheat sheet
Merge pull request #9 from wking/mailmap

.mailmap: Standardize identifiers for Lynne and Matt
Merge pull request #7 from ethanwhite/sql-cheat-sheet

SQL cheat sheet
Reorganize existing cheat sheets into topic subdirectories

This will keep things from getting too cluttered as the workshop
information fills in.