Replace "@(\w|-|_)+" with @github

[jonathanpeppers]

The Regex I used would find any text with @, then letters, numbers, hyphens, underscores. So it would stop at a space or other characters.

This worked for any text I saw in classified.csv. I'm not sure which characters are valid Github handles?

[rolfbjarne]

I found this: https://stackoverflow.com/a/30281147/183422