Integrate query middleware with query execution promise

Signed-off-by: João Victor Tozatti Risso <jvtr12@inf.ufpr.br>

src/libs/middlewares/query.js

-var libs = process.cwd() + '/libs/'
-var conn = require(libs + 'db/monet')
-var log = require(libs + 'log')(module)
-var queryExec = require(libs + 'db/query_exec')
+const libs = process.cwd() + '/libs/';
+const log = require(libs + 'log')(module);
+const execQuery = require(libs + 'db/query_exec');
 
 function query(req, res, next) {
     log.debug(req.query)
-    queryExec(req.query.text, req.query.values)
-    .then(function(result) {
-        log.debug(result)
-        console.log("PEOPO");
-        req.result = result
-        next()
-    })
+    execQuery(req.query.text, req.query.values).then((result) => {
+        log.debug(result);
+        req.result = result;
+        next();
+    }, (error) => {
+        next(error);
+    });
 }
 
-module.exports = query
+module.exports = query;