underscore helper `_` for random subdomain

Adds underscore helper _ for a random subdomains (skipping the prompt).

v0.17.6

• Updates the tests for using Surge within Yargs and Minimist-based CLIs
• Fixes #182 for the other Surge commands

v0.17.2

• Fixes surge ssl command
• Adds new tests for surge plus and surge ssl
• Adds config files to run tests Appveyor and Travis CI

v0.7.4

Breaking Changes!!!

Those deploying apps built with harp will need to pass in the --build flag or -b for short. You still get clean URLs and all that jazz. Surge.sh no longer does the harp compile step before distributing on the CDN without the --build flag. To upgrade

npm install -g surge

you many need to run as sudo