Add tests

lib/Issue.js

@@ -248,15 +248,15 @@ class Issue extends Requestable {
    }
 
   /**
-   * Add a label to an issue
+   * Set labels to an issue
    * @see https://developer.github.com/v3/issues/labels/#add-labels-to-an-issue
    * @param {number} issue - the id of the issue to comment on
-   * @param {array} label - the names of the label to add to the issue
+   * @param {array} labels - the names of the labels to add to the issue
    * @param {Requestable.callback} [cb] - will receive the status
    * @return {Promise} - the promise for the http request
    */
-   addLabel(issue, label, cb) {
-      return this._request('POST', `/repos/${this.__repository}/issues/${issue}/labels`, label, cb);
+   setLabels(issue, labels, cb) {
+      return this._request('POST', `/repos/${this.__repository}/issues/${issue}/labels`, labels, cb);
    }
 
   /**

test/issue.spec.js

@@ -169,6 +169,24 @@ describe('Issue', function() {
          }));
       });
 
+      it('should set labels to an issue', function(done) {
+         remoteIssues.setLabels(issueCommentId, ['test label'], assertSuccessful(done, function(err, response) {
+            console.log('aaaa', response)
+            expect(response).to.be.true();
+
+            done();
+         }));
+      });
+
+      it('should remove labels to an issue', function(done) {
+         remoteIssues.setLabels(issueCommentId, 'test label', assertSuccessful(done, function(err, response) {
+            console.log('bbbbbb', response)
+            expect(response).to.be.true();
+
+            done();
+         }));
+      });
+
       it('should create a milestone', function(done) {
          let milestone = {
             title: 'v42',