replace tab indents with 4 spaces in lib/rules/handle-callback-err.js
Merge pull request #742 from michaelficarra/no-tabs

replace tab indents with 4 spaces in lib/rules/handle-callback-err.js
fixes #743: wrap-regex rule warns on regex used in dynamic member access
Merge pull request #744 from michaelficarra/GH-743

fixes #743: wrap-regex rule warns on regex used in dynamic member access
Fixes #740 - Make sure callbacks exist before marking them as 'handled'.