use the rejectedWith check in comments tests too

Signed-off-by: Jakub Sokołowski <jakub@status.im>

test/comments.js

@@ -56,11 +56,7 @@ describe('Comments', () => {
   describe('renderComment', () => {
     it('should fail with no builds', async () => {
       builds.getBuilds.returns([])
-      try {
-        await comments.renderComment('PR-ID')
-      } catch(err) {
-        expect(err.message).to.eq('No builds exist for this PR')
-      }
+      expect(comments.renderComment('PR-ID')).rejectedWith('No builds exist for this PR')
     })
 
     it('should render correctly', async () => {

test/schema.js

@@ -29,12 +29,12 @@ describe('Schema', () => {
 
     it('can\'t be a null', () => {
       build.commit = null
-      expect(Joi.validate(build, Schema)).to.be.rejectedWith('"commit" must be a string')
+      expect(Joi.validate(build, Schema)).rejectedWith('"commit" must be a string')
     })
 
     it('can\'t be a number', async () => {
       build.commit = 1
-      expect(Joi.validate(build, Schema)).to.be.rejectedWith('"commit" must be a string')
+      expect(Joi.validate(build, Schema)).rejectedWith('"commit" must be a string')
     })
   })
 
@@ -52,7 +52,7 @@ describe('Schema', () => {
 
     it('can\'t be a number', async () => {
       build.pkg_url = 1
-      expect(Joi.validate(build, Schema)).to.be.rejectedWith('"pkg_url" must be a string')
+      expect(Joi.validate(build, Schema)).rejectedWith('"pkg_url" must be a string')
     })
   })
 })