Allows publishing to NPM automatically from travis

[JirkaChadima]

• This setup will publish every tagged commit in master branch to npmjs.org into @windingtree/lif-token
• The resulting package contains only compiled JSON files and an index.js
• This expects that travis has the NPM_TOKEN environment variable set up in Travis CI. This token should be tied to chadima.jiri@gmail.com npmjs account OR another account, but then we have to change the email field in .travis.yml. I was not able to get encrypted API keys working.
• I have also scoped the package under windingtree organization in npmjs