it('should ignore urls that have a protocol', (done) => {
   context.resolveUrl('http://foo').then(path => {
     expect(path).to.be('http://foo');
     done();
   }).catch(done);
 });
 it('should resolve a relative url to a correct server path', (done) => {
   context.resolveUrl('./foo').then(path => {
     expect(path).to.be('foo');
   }).then(done, done);
 });