Improve naming

lib/cartodb/middleware/context/apikey-credentials.js

@@ -3,8 +3,10 @@
 module.exports = function apikeyToken () {
     return function apikeyTokenMiddleware(req, res, next) {
         const apikeyCredentials = getApikeyCredentialsFromRequest(req);
+
         res.locals.api_key = apikeyCredentials.token;
-        res.locals.apikeyUsername = apikeyCredentials.username;
+        res.locals.basicAuthUsername = apikeyCredentials.username;
+
         return next();
     };
 };