Removed goji specific Context from middleware args.

This makes the middleware more generic and not depend on goji. The
middleware affected doesn't even use Context anyway.
Moved middleware to github.com/pressly/gohttpware
Root/non-Script URLs now proxy to nsqadmin if given.
Updated README and added log message to AdminProxy
Change BasicAuth signature to match gohttpware.
Add Redis base login timout for issue #14.

This commit adds functions that blocks a specific user from logging in
after X tries for Y seconds. X and Y are currently hardcoded to 7 and
300 in redis.go