fix southwestgas account no

Author: andobolocco

lib/documentTypes/southwestGasBill.js

@@ -79,13 +79,14 @@ module.exports = {
 
     // account number
     let account_number = keyValues['ACCOUNT NUMBER'];
+
     if (!account_number || !account_number.length) {
       account_number = rawText.filter((line) => (
-        line.match(/ACCOUNT NUMBER/g)
+        line.match(/ACCOUNT NUM/g)
         && line.match(/\d+/g)
       ));
 
-      account_number = account_number.length ? account_number[0].replace('ACCOUNT NUMBER: ', '') : '';
+      account_number = (/(.*) (\d+\-\d+\-\d+)/g.exec(account_number) || [])[2];
     }
 
     return {