move a simple sql query directly into query-generator to test travis

lib/dialects/mssql/query-generator.js

@@ -87,7 +87,7 @@ module.exports = (function() {
     },
 
     showTablesQuery: function () {
-      return SqlGenerator.showTableSql();
+      return 'SELECT name FROM sys.Tables;';
     },
 
     /*

lib/dialects/mssql/sql-generator.js

@@ -254,10 +254,6 @@ module.exports = {
     return escape(value,field);
   },
 
-  showTableSql: function(){
-    return 'SELECT name FROM sys.Tables;';
-  },
-
   processValue: function(val, modelAttribute){
     return processValue(val, modelAttribute);
   },