fix: fix broken stat tests (#236)

Tests broke due to c4934ca [1].

If promises are used, you needn't pass `done` as parameter of
the callback in.

[1]: c4934ca#diff-0a6449ecfa8b9e3d807f53dde24eca71R66

Author: vmx

js/src/files.js

@@ -919,8 +919,8 @@ module.exports = (common) => {
       })
     })
 
-    describe('.lsPullStream', function (done) {
-      before((done) => {
+    describe('.lsPullStream', () => {
+      before(function (done) {
         // TODO: https://github.com/ipfs/js-ipfs-api/issues/339
         if (!isNode) { this.skip() }
 

js/src/stats.js

@@ -63,7 +63,7 @@ module.exports = (common) => {
       })
     })
 
-    it('.bw Promise', function (done) {
+    it('.bw Promise', function () {
       if (!withGo) {
         console.log('Not supported in js-ipfs yet')
         this.skip()