fixed a bug that made README.md unavailanle to npm

README.md could not be read so in NPM respository (https://www.npmjs.org/package/karma-phantomjs-launcher)
it showed the following error:
ERROR: No README data found!

Also when people use this package, npm install shows the following error:
npm WARN package.json karma-phantomjs-launcher@0.1.4 No README data

closes #39