auto build unicode categories

[waleedsamy]

pre install you shoul remove all secret from .travis.yml and generate yours by next script

node_modules/.bin/travis-encrypt --add -r dodo/node-unicodetable GH_REF=github.com/dodo/node-unicodetable.git
node_modules/.bin/travis-encrypt --add -r dodo/node-unicodetable GH_USER=dodo
# token is generated from https://github.com/settings/tokens
node_modules/.bin/travis-encrypt --add -r dodo/node-unicodetable GH_TOKEN={TOKEN}

how it work

• travis will build master branch only then publish unicode categories to master back
• nightli will make previous job happen dialy

  changes :

• no need to postinstall script in package.json
• remove category folder from .gitignore
• travis-encrypt not support node js version 0.8 so all solution not goin to work with it and i droped this version from .travis.yml

  Note :

• should configure travis to run only one job to make sure that there is no any race conditions while building and no conflict occur while travis push categories back to master

this pull request will resolve issues #16 #18 #19