Cleanup grunt tasks for running specs

- [x] `grunt test:unit` - run karma without compiling coffeescripts
- [x] `grunt test:unit-coverage` - compile coffeescripts, run specs with coverage
- [ ] speedup `grunt:unit-coverage` - compile only coffeescripts not the entire app
- [ ] ability to select coverage reporter `grunt test:unit-coverage --reporter=html/text`
- [ ] cleanup karma config files
- [ ] review other grunt tasks
- [x] `grunt test:e2e` - run angularjs e2e scenarios
- [x] `grunt test:capserjs` - run casperjs scenarios
- [ ] fix https://github.com/lucassus/angular-seed/issues/41
- [ ] simple script for running karma (`./script/karma`)
- [ ] tutorial: how to run karma in Intellij