Issue installing CBTravel on OS X

I am trying to follow the instructions found at the link below:

I have installed node.js but when I run the npm install couchbase does a bunch of stuff and then shows this:

npm install couchbase
npm ERR! tar.unpack untar error /var/root/.npm/couchbase/2.1.3/package.tgz
npm ERR! Darwin 15.3.0
npm ERR! argv “/usr/local/bin/node” “/usr/local/bin/npm” “install” “couchbase”
npm ERR! node v4.2.6
npm ERR! npm v2.14.12
npm ERR! path /usr/node_modules
npm ERR! code EPERM
npm ERR! errno -1
npm ERR! syscall mkdir

npm ERR! Error: EPERM: operation not permitted, mkdir ‘/usr/node_modules’
npm ERR! at Error (native)
npm ERR! { [Error: EPERM: operation not permitted, mkdir ‘/usr/node_modules’]
npm ERR! errno: -1,
npm ERR! code: ‘EPERM’,
npm ERR! syscall: ‘mkdir’,
npm ERR! path: ‘/usr/node_modules’,
npm ERR! fstream_type: ‘Directory’,
npm ERR! fstream_path: ‘/usr/node_modules/couchbase’,
npm ERR! fstream_class: ‘DirWriter’,
npm ERR! fstream_stack:
npm ERR! [ ‘/usr/local/lib/node_modules/npm/node_modules/fstream/lib/writer.js:171:25’,
npm ERR! ‘/usr/local/lib/node_modules/npm/node_modules/mkdirp/index.js:47:53’,
npm ERR! ‘FSReqWrap.oncomplete (fs.js:82:15)’ ] }
npm ERR!
npm ERR! Please try running this command again as root/Administrator.
npm ERR! Darwin 15.3.0
npm ERR! argv “/usr/local/bin/node” “/usr/local/bin/npm” “install” “couchbase”
npm ERR! node v4.2.6
npm ERR! npm v2.14.12
npm ERR! path npm-debug.log.36aa83f862c50be476891cda3f6d26fa
npm ERR! code EPERM
npm ERR! errno -1
npm ERR! syscall open

npm ERR! Error: EPERM: operation not permitted, open ‘npm-debug.log.36aa83f862c50be476891cda3f6d26fa’
npm ERR! at Error (native)
npm ERR! { [Error: EPERM: operation not permitted, open ‘npm-debug.log.36aa83f862c50be476891cda3f6d26fa’]
npm ERR! errno: -1,
npm ERR! code: ‘EPERM’,
npm ERR! syscall: ‘open’,
npm ERR! path: ‘npm-debug.log.36aa83f862c50be476891cda3f6d26fa’ }
npm ERR!
npm ERR! Please try running this command again as root/Administrator.

npm ERR! Please include the following file with any support request:
npm ERR! /usr/npm-debug.log

I have tried using sudo as well as root and it does not work.

I am on El Capitan. Any help would be appreciated.

Thanks,

Carl