Remove leakage

It hasn’t been updated to support Node 12: andywer/leakage#34

package.json

@@ -84,7 +84,6 @@
     "bundlesize": "^0.18.0",
     "eslint": "^6.5.1",
     "http-server": "^0.12.0",
-    "leakage": "^0.5.0",
     "mocha": "^6.2.2",
     "request": "^2.81.0",
     "request-promise": "^4.2.1",

test/app.test.js

@@ -1,5 +1,4 @@
 const assert = require('assert');
-const iterate = require('leakage').iterate;
 const rp = require('request-promise');
 const app = require('../src/app');
 
@@ -19,19 +18,6 @@ describe('Feathers application tests', () => {
     );
   });
 
-  it('does not leak', async function() {
-    this.timeout(90000);
-    await iterate.async(async () => {
-      return rp('http://localhost:8080/events/2019/01/06/trail-1898/');
-    }, {
-      iterations: 2
-    }).catch(error => {
-      const increaseSize = error.message.split('\n')[0].split('by')[1].trim();
-      assert.ok(parseFloat(increaseSize) < 6.5, `Increase was ${increaseSize}`);
-      assert.ok(increaseSize.indexOf('MB') > 0, 'Increase is in MB');
-    });
-  });
-
   xdescribe('404', function() {
     it('shows a 404 HTML page', () => {
       return rp({