Move development to master branch, use gh-pages as deploy branch

[gr2m]

• move index.html into /demo folder
• make initials.js commonjs-only, just one module.exports = initials, without checking for define, and the wrapper functions anymore. Rename file to index.js and make it the "main" in package.json
• add a local dev server that serves /demo and dynamically browserifies initials and serves it at /initials.js. beefy could be a simple option for that, the npm start task could look like beefy ./index.js --cwd=./demo
• add a build task, build into /dist. Add /dist to gitignore
• Add .npmignore (only coverage/ in it, so that /dist gets added to published pacakge)
• Add deploy task, which is 1. build, 2. copy build initials.js file to /demo, 3. gh-pages-deploy of /demo folder
• remove the release.branch setting in package.json
• remove branches setting in .travis.yml

That should be it :) @zoepage want to give this a go? Does it all make sense?

[zoepage]

As far as well, it does. If I have any questions, I'll ping you :)