branch

• ch04-fixes
• ch05-fixes
• check-ch04-lessons
• cleanup-repo
• day2-post-teaching-fixes
• day3-post-teaching-fixes
• day4-post-teaching-fixes
• day9-updates
• day10-updates
• file-format-fixes
• fix-gh-pages-build
• fix-testing-module
• fix-travis-errors
• gh-pages
• markdown-fixes
• master
• packaging-lesson-fixes

tag