v6.2.8

🐛 Bug Fix

• gzipped files should have .gz as the extension, not .gzip (#326) @bjornstar
• fix options.sourceFileName gennerate bug (#260) @creeperyang

📝 Documentation

• Update README docs for cacheDirectory's actual behaviour (#245) @sohkai
• updates docs re: transform-runtime (#197) @gbrassey

🏠 Internal

• Use eslint and nyc (#321) @danez
• Adjust travis config (#320) @danez
• Use babel to compile babel-loader (#319) @danez