added minification

* replaced 3rd party source files with minified versions
* added and configured grunt-uglify
Merge branch 'uglify' of github.com:codepogo/shipscope into uglify
uglified shipscope:

* created two uglified files: `shipscope.min.js` and `shipscope-background.min.js`
* updated `popup.html` and `background.html` to use the uglified files.
* added a clean task and updated the `build` task with `clean` and `uglify`.
* updated the `karma` task with `clean` and `uglify`.
remove popup.html from karma conf
remove version from zipfile.

* having the version made it tricky to use the Codeship deploy step to
  send the zipfile to s3. I would like to figure that out, because it
  would be nice to have all versions archived on s3.
Merge pull request #10 from codepogo/uglify

added minification