title: Strongloop: currentContext not available in middleware?
body: <p>I have my middlewares configured in Strongloop in the following way in middleware.json:</p>
  
  <pre><code>{ 
  "initial:before": {
        "loopback#favicon": {}
    },
    "initial": {
      "compression": {},
      "cors": {
        "params": {
          "origin": true,
          "credentials": true,
          "maxAge": 86400
        }
      },
      "helmet#xssFilter": {},
      "helmet#frameguard": {
        "params": [
          "deny"
        ]
      },
      "helmet#hsts": {
        "params": {
          "maxAge": 0,
          "includeSubdomains": true
        }
      },
      "helmet#hidePoweredBy": {},
      "helmet#ieNoOpen": {},
      "helmet#noSniff": {},
      "helmet#noCache": {
        "enabled": false
      },
      "express-jwt": {
        "paths": [
          "${restApiRoot}"
        ],
        "params": {
          "secret": "secret"
        }
      }
    },
    "session": {},
    "auth": {
      "./middleware/token-validation": {
        "paths": [
          "${restApiRoot}"
        ]
      }
    },
    "parse": {},
    "routes": {
      "loopback#rest": {
        "paths": [
          "${restApiRoot}"
        ]
      }
    },
    "files": {},
    "final": {
      "loopback#urlNotFound": {}
    },
    "final:after": {
      "loopback#errorHandler": {}
    }
  }
  </code></pre>
  
  <p>This file was genereated by Strongloop, except the "auth" middleware was added manually.
  In this middleware (token-validation.js) I want to access the currentContext like this:</p>
  
  <pre><code>return function tokenValidation(req, res, next) {
    var app = req.app;
    var ctx = app.loopback.getCurrentContext();
    console.log(ctx);
  });
  </code></pre>
  
  <p>However, the ctx object is always null.... Any ideas?</p>