gistfile1.txt

npm install --save-dev babel-core
sudo npm install --save-dev babel-core
which npm 
//that^ appeared to be a symlink to: /home/konrad/.nvm/versions/node/v6.4.0/lib/node_modules/npm/bin/npm-cli.js so:
ls -lha /home/konrad/.nvm/versions/node/v6.4.0/lib/node_modules/npm/bin
//result:
drwxrwxr-x  2 konrad konrad 4.0K Aug 15 16:11 node-gyp-bin
-rwxrwxr-x  1 konrad konrad  833 May 27 02:14 npm
-rwxrwxr-x  1 konrad konrad 2.0K Jul 15 00:00 npm-cli.js
-rw-rw-r--  1 konrad konrad  464 May 27 01:56 npm.cmd
-rwxrwxr-x  1 konrad konrad  513 Jul 15 00:00 read-package-json.js
//result
sudo: npm: command not found