Remove unnecessary 'apt-get update'.

The nodesource install runs apt-get update anyway, and I think we're ok with an earlier version of curl.
Remove unnecessary stdout redirects
Make hubot respond with bug info anytime anyone mentions a bug in irc, even if they don't mention hubot
Bugzilla credentials are now unnecessary

Read-only access to bugs.sfolab.ibm.com no longer requires credentials.
Send all bug info in one irc line