failed to install with:
npm ERR! Darwin 15.3.0
npm ERR! argv "/usr/local/Cellar/node/5.6.0/bin/node" "/usr/local/bin/npm" "install" "-g" "appium@1.5.1"
npm ERR! node v5.6.0
npm ERR! npm v3.6.0
npm ERR! path /usr/local/bin/appium
npm ERR! code EEXIST
npm ERR! Refusing to delete /usr/local/bin/appium: ../lib/node_modules/appium/bin/appium.js symlink target is not controlled by npm /usr/local
npm ERR! File exists: /usr/local/bin/appium
npm ERR! Move it away, and try again.
npm ERR! Please include the following file with any support request:
npm ERR! /Users/Aleksei/npm-debug.log
npm ERR! code 1
subsequent "npm install -g appium@1.4.16" completing successfully