ruby on rails - npm error: tunneling socket could not be established, cause=connect ETIMEDOUT -

i have app uses rails framework , implements angularjs part of front end.

i have pushed heroku , have heroku toolbelt installed, when try migrate db using "heroku run rake db:migrate" receive following error(s):

installing core plugins heroku-cli-addons, heroku-apps, heroku-fork, heroku-git, heroku-local, heroku-run, heroku-status... error installing package. try running again gode_debug=info see more output.  !    `run` not heroku command.  !    perhaps meant `-h`, `2fa`, `auth`, `join`, `open`, `orgs`, `pg`, `ps` or `rake`.  !    see `heroku help` list of available commands. 

i run command "gode_debug=info heroku run rake db:migrate" , receive error:

npm err! darwin 14.5.0 npm err! argv "/users/christopher_pelnar/.heroku/node-v4.2.1-darwin-x64/bin/node" "/users/christopher_pelnar/.heroku/node-v4.2.1-darwin-x64/lib/node_modules/npm/cli.js" "install" "heroku-cli-addons" "heroku-apps" "heroku-fork" "heroku-git" "heroku-local" "heroku-run" "heroku-status" "--loglevel=info" npm err! node v4.2.1 npm err! npm  v3.3.8 npm err! code econnreset  npm err! network tunneling socket not established, cause=connect etimedout 198.105.254.228:8080 npm err! network not problem npm npm err! network , related network connectivity. npm err! network in cases behind proxy or have bad network settings. npm err! network npm err! network if behind proxy, please make sure npm err! network 'proxy' config set properly.  see: 'npm config'  npm err! please include following file support request: npm err!     /users/christopher_pelnar/.heroku/npm-debug.log 

removing proxy settings resolved issue:

npm config rm proxy
npm config rm https-proxy