Merge pull request #371 from zensh/master

remove unnecessary "require('http')"
move gitter badge
remove x-powered-by. Closes #372
add screencast link

we probably should not get too crazy with links here, and maintain them in the Wiki,
but this one is really well done!
Update response.md
remove the 'x-powered-by' in context test since it has been removed
Merge pull request #377 from Horx/master

remove the 'x-powered-by' in context test since it has been removed