Add route /class/years

src/libs/routes/class.js

@@ -26,6 +26,12 @@ classApp.get('/year_range', (req, res, next) => {
     next();
 }, query, response('range'));
 
+classApp.get('/years', (req, res, next) => {
+    req.sql.from('turma')
+    .field('DISTINCT turma.ano_censo', 'year');
+    next();
+}, query, response('years'));
+
 classApp.get('/location', (req, res, next) => {
     req.sql = squel.select()
     .field('id')