title: when installing @angular/cli in ubuntu error ocurred
body: <pre><code>gyp ERR! configure error 
  gyp ERR! stack Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/@angular/cli/node_modules/node-sass/build'
  gyp ERR! System Linux 4.8.0-56-generic
  gyp ERR! command "/usr/local/bin/node" "/usr/local/lib/node_modules/@angular/cli/node_modules/node-gyp/bin/node-gyp.js" "rebuild" "--verbose" "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="
  gyp ERR! cwd /usr/local/lib/node_modules/@angular/cli/node_modules/node-sass
  gyp ERR! node -v v7.10.0
  gyp ERR! node-gyp -v v3.6.2
  gyp ERR! not ok 
  </code></pre>