angular-cli compiling

@nshmyrev I am using the angular-demo，so i must compiling the angular-cli，when i run yarn to install angular dependence，met follows errors，can give me some advice？thanks！

```
yarn install v1.22.17
[1/5] Validating package.json...
[2/5] Resolving packages...
[3/5] Fetching packages...
error An unexpected error occurred: "https://saucelabs.com/downloads/sc-4.6.4-linux.tar.gz: Request failed \"406 Not Acceptable\"".
info If you think this is a bug, please open a bug report with the information provided in "/home/ybZhang/software/angular-cli/yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/instal
```