Cache phantomjs library

[exec] Found PhantomJS at /usr/bin/phantomjs ...verifying
17:50:55      [exec] PhantomJS detected, but wrong version 1.9.0 @ /usr/bin/phantomjs.
17:50:55      [exec] Downloading https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-1.9.8-linux-x86_64.tar.bz2
17:50:55      [exec] Saving to /tmp/phantomjs/phantomjs-1.9.8-linux-x86_64.tar.bz2
17:50:55      [exec] Receiving...
17:50:56      [exec] Error requesting archive.
17:50:56      [exec] Status: 403
17:50:56      [exec] Request options: {
17:50:56      [exec]   "uri": "https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-1.9.8-linux-x86_64.tar.bz2",
17:50:56      [exec]   "encoding": null,
17:50:56      [exec]   "followRedirect": true,
17:50:56      [exec]   "headers": {},
17:50:56      [exec]   "strictSSL": true
17:50:56      [exec] }
17:50:56      [exec] Response headers: {
17:50:56      [exec]   "x-amz-request-id": "64C0E845D1EC2153",
17:50:56      [exec]   "x-amz-id-2": "B6oE9Exp+hzBNYXjpS6wuHMZYiSHbVlXwL0AT1KJaey9y0AQE5ePk2+XYxpvi7sqe3CgpoHxtwU=",
17:50:56      [exec]   "content-type": "application/xml",
17:50:56      [exec]   "transfer-encoding": "chunked",
17:50:56      [exec]   "date": "Mon, 18 Apr 2016 15:50:55 GMT",
17:50:56      [exec]  
17:50:56      [exec]  "server": "AmazonS3",
17:50:56      [exec]   "connection": "close"
17:50:56      [exec] }
17:50:56      [exec] Make sure your network and proxy settings are correct.
17:50:56      [exec] 
17:50:56      [exec] If you continue to have issues, please report this full log at https://github.com/Medium/phantomjs
17:50:59      [exec] npm WARN optional dep failed, continuing fsevents@1.0.6
17:51:00      [exec] npm ERR! Linux 3.13.0-85-generic
17:51:00      [exec] npm ERR! argv "/opt/build/tools/node-v4.4.2-linux-x64/bin/node" "/usr/local/bin/npm" "install"
17:51:00      [exec] npm ERR! node v4.4.2
17:51:00      [exec] npm ERR! npm  v2.15.1
17:51:00      [exec] npm ERR! code ELIFECYCLE
17:51:00      [exec] 
17:51:00      [exec] npm ERR! phantomjs@1.9.19 install: `node install.js`
17:51:00      [exec] npm ERR! Exit status 1
17:51:00      [exec] npm ERR! 
17:51:00      [exec] npm ERR! Failed at the phantomjs@1.9.19 install script 'node install.js'.
17:51:00      [exec] npm ERR! This is most likely a problem with the phantomjs package,
17:51:00      [exec] npm ERR! not with npm itself.
17:51:00      [exec] npm ERR! Tell the author that this fails on your system:
17:51:00      [exec] npm ERR!     node install.js
17:51:00      [exec] npm ERR! You can get information on how to open an issue for this project with:
17:51:00      [exec] npm ERR!     npm bugs phantomjs
17:51:00      [exec] npm ERR! Or if that isn't available, you can get their info via:
17:51:00      [exec] npm ERR! 
17:51:00      [exec] npm ERR!     npm owner ls phantomjs
17:51:00      [exec] npm ERR! There is likely additional logging output above.
17:51:00      [exec] 
17:51:00      [exec] npm ERR! Please include the following file with any support request:
17:51:00      [exec] npm ERR!     /mnt/workspace/ondemand-testandpush-slacoin/addons/nuxeo-salesforce/nuxeo-salesforce-web/npm-debug.log