fix regex in trigger to accept '@' character

src/scripts/pagerduty.coffee

@@ -129,7 +129,7 @@ module.exports = (robot) ->
 
   # hubot pager trigger <user> <severity> <msg> - create a new incident with <msg> and assign it to <user>. Severity must be one of: critical, error, warning or info.
   # hubot pager trigger <schedule> <severity> <msg> - create a new incident with <msg> and assign it the user currently on call for <schedule>. Severity must be one of: critical, error, warning or info.
-  robot.respond /(pager|major)( me)? (?:trigger|page) ([\w\-]+)( (critical|error|warning|info) )?(.+)$/i, (msg) ->
+  robot.respond /(pager|major)( me)? (?:trigger|page) (?:@?)([\w\-]+)( (critical|error|warning|info) )?(.+)$/i, (msg) ->
     msg.finish()
 
     if pagerduty.missingEnvironmentForApi(msg)