"EINVRES Request to https://bower.herokuapp.com/packages/ember failed with 502" this error occurs when you are trying to download bower packages.
You have to update the bower to solve this issue. If you have npm installed, you can directly write below command in npm
If still the problem persist, you can directly update the .bowerrc file with the following data.
.bowerrc file is located in the same directory where other file like bower_components directory and bower.json file is located. If you can't find this file, you can create a new file yourself in the same directory.